<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with Wdesk from Workiva-->
<!--Copyright 2021 Workiva-->
<!--r:38203de9-ac80-489b-88ea-2598c585e40f,g:2d80787e-8907-43bd-8be2-2f5b7219c531-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/CoverPage" xlink:type="simple" xlink:href="rxt-20201231.xsd#CoverPage"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/CoverPage" xlink:type="extended" id="id2538bfa959247c0b2a48a8de669600c_CoverPage"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/ConsolidatedBalanceSheets" xlink:type="simple" xlink:href="rxt-20201231.xsd#ConsolidatedBalanceSheets"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/ConsolidatedBalanceSheets" xlink:type="extended" id="ib3396008afa34f7884b651841cb4ad65_ConsolidatedBalanceSheets"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/ConsolidatedBalanceSheetsParenthetical" xlink:type="simple" xlink:href="rxt-20201231.xsd#ConsolidatedBalanceSheetsParenthetical"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/ConsolidatedBalanceSheetsParenthetical" xlink:type="extended" id="i7f6f54d9c40b45b387d4364bb0aba52c_ConsolidatedBalanceSheetsParenthetical"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/ConsolidatedStatementsofComprehensiveLoss" xlink:type="simple" xlink:href="rxt-20201231.xsd#ConsolidatedStatementsofComprehensiveLoss"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/ConsolidatedStatementsofComprehensiveLoss" xlink:type="extended" id="ifc7dc8be6513497f923ba6619146f521_ConsolidatedStatementsofComprehensiveLoss"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/ConsolidatedStatementsofCashFlows" xlink:type="simple" xlink:href="rxt-20201231.xsd#ConsolidatedStatementsofCashFlows"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/ConsolidatedStatementsofCashFlows" xlink:type="extended" id="i3d5866fce16b47b98cafa459b471e3b0_ConsolidatedStatementsofCashFlows"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/ConsolidatedStatementsofStockholdersEquity" xlink:type="simple" xlink:href="rxt-20201231.xsd#ConsolidatedStatementsofStockholdersEquity"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/ConsolidatedStatementsofStockholdersEquity" xlink:type="extended" id="i5dd5b97007004b7dbbd79e46fae827f0_ConsolidatedStatementsofStockholdersEquity">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_b645736a-00c4-4a7e-b704-56f573d44a63" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e4a9fb5a-590b-407b-96bd-dd0b197a6642" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b645736a-00c4-4a7e-b704-56f573d44a63" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e4a9fb5a-590b-407b-96bd-dd0b197a6642" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharesOutstanding_776af5d7-0fb8-44dd-8d06-bd23604881f7" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e4a9fb5a-590b-407b-96bd-dd0b197a6642" xlink:to="loc_us-gaap_SharesOutstanding_776af5d7-0fb8-44dd-8d06-bd23604881f7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_d5bb5589-39d3-4065-9582-f5a5d2ab994b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e4a9fb5a-590b-407b-96bd-dd0b197a6642" xlink:to="loc_us-gaap_StockholdersEquity_d5bb5589-39d3-4065-9582-f5a5d2ab994b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_3bcf193a-81b3-412d-9580-698056e6ae7e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e4a9fb5a-590b-407b-96bd-dd0b197a6642" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_3bcf193a-81b3-412d-9580-698056e6ae7e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_97fc0ff6-3337-4233-af74-2c17d3d81cb7" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e4a9fb5a-590b-407b-96bd-dd0b197a6642" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_97fc0ff6-3337-4233-af74-2c17d3d81cb7" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountingStandardsUpdateExtensibleList_6a50dd90-03f9-46eb-a151-b397f61ddad6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccountingStandardsUpdateExtensibleList"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e4a9fb5a-590b-407b-96bd-dd0b197a6642" xlink:to="loc_us-gaap_AccountingStandardsUpdateExtensibleList_6a50dd90-03f9-46eb-a151-b397f61ddad6" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_0e6d1d45-54b7-4f87-b92a-93e4b1f9570a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e4a9fb5a-590b-407b-96bd-dd0b197a6642" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_0e6d1d45-54b7-4f87-b92a-93e4b1f9570a" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_e9cd9b89-1407-452a-9fd8-c2b6e38006c8" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e4a9fb5a-590b-407b-96bd-dd0b197a6642" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_e9cd9b89-1407-452a-9fd8-c2b6e38006c8" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans_21eec718-f234-4b40-819b-adfadf39ce2d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e4a9fb5a-590b-407b-96bd-dd0b197a6642" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans_21eec718-f234-4b40-819b-adfadf39ce2d" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueEmployeeStockPurchasePlan_e151cab5-c7e3-4824-8878-3cd0201c1c4a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueEmployeeStockPurchasePlan"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e4a9fb5a-590b-407b-96bd-dd0b197a6642" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueEmployeeStockPurchasePlan_e151cab5-c7e3-4824-8878-3cd0201c1c4a" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodShares_dcceb1ae-7f2e-4bca-b6b8-9976d6e561e8" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockRepurchasedAndRetiredDuringPeriodShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e4a9fb5a-590b-407b-96bd-dd0b197a6642" xlink:to="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodShares_dcceb1ae-7f2e-4bca-b6b8-9976d6e561e8" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodValue_6b1770ea-6056-49aa-9f1f-c1d64b7efba2" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockRepurchasedAndRetiredDuringPeriodValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e4a9fb5a-590b-407b-96bd-dd0b197a6642" xlink:to="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodValue_6b1770ea-6056-49aa-9f1f-c1d64b7efba2" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_AdjustmentsToAdditionalPaidInCapitalCashUsedToSettleShareBasedAwards_f9431a06-8c27-4fd8-ad0b-5fb7de9b95ff" xlink:href="rxt-20201231.xsd#rxt_AdjustmentsToAdditionalPaidInCapitalCashUsedToSettleShareBasedAwards"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e4a9fb5a-590b-407b-96bd-dd0b197a6642" xlink:to="loc_rxt_AdjustmentsToAdditionalPaidInCapitalCashUsedToSettleShareBasedAwards_f9431a06-8c27-4fd8-ad0b-5fb7de9b95ff" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_4ec29f53-ebc1-4197-841e-f145c2078a23" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e4a9fb5a-590b-407b-96bd-dd0b197a6642" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_4ec29f53-ebc1-4197-841e-f145c2078a23" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_640654bb-223e-4f5c-bcba-74ca688384c9" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e4a9fb5a-590b-407b-96bd-dd0b197a6642" xlink:to="loc_us-gaap_NetIncomeLoss_640654bb-223e-4f5c-bcba-74ca688384c9" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_55d79763-abb5-45fe-be3a-123820d7b3c8" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e4a9fb5a-590b-407b-96bd-dd0b197a6642" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_55d79763-abb5-45fe-be3a-123820d7b3c8" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharesOutstanding_ed504636-8f70-4c41-a77b-0d56645f7128" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SharesOutstanding"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_5027f9e5-7739-470c-bf79-3e5b1791ebd6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_7744f43b-c03c-4ac0-82fa-56c030b2e696" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_b645736a-00c4-4a7e-b704-56f573d44a63" xlink:to="loc_us-gaap_StatementTable_7744f43b-c03c-4ac0-82fa-56c030b2e696" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_ca6add29-9397-4e3d-9292-53915564b072" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_7744f43b-c03c-4ac0-82fa-56c030b2e696" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_ca6add29-9397-4e3d-9292-53915564b072" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_ca6add29-9397-4e3d-9292-53915564b072_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_ca6add29-9397-4e3d-9292-53915564b072" xlink:to="loc_us-gaap_EquityComponentDomain_ca6add29-9397-4e3d-9292-53915564b072_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_c869ba69-95b9-423a-941c-aa7de0009ff1" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_ca6add29-9397-4e3d-9292-53915564b072" xlink:to="loc_us-gaap_EquityComponentDomain_c869ba69-95b9-423a-941c-aa7de0009ff1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_b146e662-c9f5-40d1-aa28-9da93eda556e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_c869ba69-95b9-423a-941c-aa7de0009ff1" xlink:to="loc_us-gaap_CommonStockMember_b146e662-c9f5-40d1-aa28-9da93eda556e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_a2f08f99-1f3e-44da-ac4e-3895666ae11d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_c869ba69-95b9-423a-941c-aa7de0009ff1" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_a2f08f99-1f3e-44da-ac4e-3895666ae11d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_85f9859f-6832-47d9-bf30-49c77bd0ee69" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_c869ba69-95b9-423a-941c-aa7de0009ff1" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_85f9859f-6832-47d9-bf30-49c77bd0ee69" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_a0821b59-53fc-4af2-b720-91fa89b2a10c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetainedEarningsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_c869ba69-95b9-423a-941c-aa7de0009ff1" xlink:to="loc_us-gaap_RetainedEarningsMember_a0821b59-53fc-4af2-b720-91fa89b2a10c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CumulativeEffectPeriodOfAdoptionAxis_6419cc51-8947-4931-a035-bbe93eb3d288" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_CumulativeEffectPeriodOfAdoptionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_7744f43b-c03c-4ac0-82fa-56c030b2e696" xlink:to="loc_srt_CumulativeEffectPeriodOfAdoptionAxis_6419cc51-8947-4931-a035-bbe93eb3d288" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CumulativeEffectPeriodOfAdoptionDomain_6419cc51-8947-4931-a035-bbe93eb3d288_default" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_CumulativeEffectPeriodOfAdoptionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_CumulativeEffectPeriodOfAdoptionAxis_6419cc51-8947-4931-a035-bbe93eb3d288" xlink:to="loc_srt_CumulativeEffectPeriodOfAdoptionDomain_6419cc51-8947-4931-a035-bbe93eb3d288_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CumulativeEffectPeriodOfAdoptionDomain_e555a469-5b52-4021-9be2-f7adafbb6b07" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_CumulativeEffectPeriodOfAdoptionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_CumulativeEffectPeriodOfAdoptionAxis_6419cc51-8947-4931-a035-bbe93eb3d288" xlink:to="loc_srt_CumulativeEffectPeriodOfAdoptionDomain_e555a469-5b52-4021-9be2-f7adafbb6b07" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CumulativeEffectPeriodOfAdoptionAdjustmentMember_814f8e0b-3e63-46c5-a04a-59d4b7dd0828" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_CumulativeEffectPeriodOfAdoptionAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_CumulativeEffectPeriodOfAdoptionDomain_e555a469-5b52-4021-9be2-f7adafbb6b07" xlink:to="loc_srt_CumulativeEffectPeriodOfAdoptionAdjustmentMember_814f8e0b-3e63-46c5-a04a-59d4b7dd0828" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.rackspace.com/role/CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPolicies" xlink:type="simple" xlink:href="rxt-20201231.xsd#CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPolicies"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPolicies" xlink:type="extended" id="i5e484f19200d4315bab9edc23451dc8a_CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPolicies"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPoliciesPolicies" xlink:type="simple" xlink:href="rxt-20201231.xsd#CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPoliciesPolicies"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPoliciesPolicies" xlink:type="extended" id="ie1f7be98935d4c61a16037fc01ce85c8_CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPoliciesPolicies"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPoliciesTables" xlink:type="simple" xlink:href="rxt-20201231.xsd#CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPoliciesTables"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPoliciesTables" xlink:type="extended" id="i507f6f3b5b3b4b2f8eb219bf1839969c_CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPoliciesTables"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPoliciesSaleofStockDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPoliciesSaleofStockDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPoliciesSaleofStockDetails" xlink:type="extended" id="i5a1c85f8281b4feb9793d1e20f26bee1_CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPoliciesSaleofStockDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsidiaryOrEquityMethodInvesteeLineItems_aa8474e4-86f3-4267-9d12-4a9914385ac1" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsidiaryOrEquityMethodInvesteeLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityNoteStockSplitConversionRatio1_8ca8325a-48d7-4e9a-895a-e38b02abc815" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockholdersEquityNoteStockSplitConversionRatio1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiaryOrEquityMethodInvesteeLineItems_aa8474e4-86f3-4267-9d12-4a9914385ac1" xlink:to="loc_us-gaap_StockholdersEquityNoteStockSplitConversionRatio1_8ca8325a-48d7-4e9a-895a-e38b02abc815" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_5f950e49-7201-472d-ae37-49b952df05cf" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiaryOrEquityMethodInvesteeLineItems_aa8474e4-86f3-4267-9d12-4a9914385ac1" xlink:to="loc_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_5f950e49-7201-472d-ae37-49b952df05cf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockPricePerShare_4b038319-a703-4cea-8ded-9577aa322751" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SaleOfStockPricePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiaryOrEquityMethodInvesteeLineItems_aa8474e4-86f3-4267-9d12-4a9914385ac1" xlink:to="loc_us-gaap_SaleOfStockPricePerShare_4b038319-a703-4cea-8ded-9577aa322751" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockConsiderationReceivedOnTransaction_d5f15178-bf13-4565-bc5e-c3aada1d8341" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SaleOfStockConsiderationReceivedOnTransaction"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiaryOrEquityMethodInvesteeLineItems_aa8474e4-86f3-4267-9d12-4a9914385ac1" xlink:to="loc_us-gaap_SaleOfStockConsiderationReceivedOnTransaction_d5f15178-bf13-4565-bc5e-c3aada1d8341" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_PaymentOfStockIssuanceCostsExcludingOfferingExpenses_487ddf39-d654-4d41-9065-39370f826f47" xlink:href="rxt-20201231.xsd#rxt_PaymentOfStockIssuanceCostsExcludingOfferingExpenses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiaryOrEquityMethodInvesteeLineItems_aa8474e4-86f3-4267-9d12-4a9914385ac1" xlink:to="loc_rxt_PaymentOfStockIssuanceCostsExcludingOfferingExpenses_487ddf39-d654-4d41-9065-39370f826f47" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_PaymentsOfStockIssuanceCostsOfferingExpenses_5192d92c-d181-49e9-a1a0-6e0139c8292b" xlink:href="rxt-20201231.xsd#rxt_PaymentsOfStockIssuanceCostsOfferingExpenses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiaryOrEquityMethodInvesteeLineItems_aa8474e4-86f3-4267-9d12-4a9914385ac1" xlink:to="loc_rxt_PaymentsOfStockIssuanceCostsOfferingExpenses_5192d92c-d181-49e9-a1a0-6e0139c8292b" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSubsidiaryOrEquityMethodInvesteeTable_a9d24740-b55f-4d9e-b19f-c9360685dbf7" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfSubsidiaryOrEquityMethodInvesteeTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SubsidiaryOrEquityMethodInvesteeLineItems_aa8474e4-86f3-4267-9d12-4a9914385ac1" xlink:to="loc_us-gaap_ScheduleOfSubsidiaryOrEquityMethodInvesteeTable_a9d24740-b55f-4d9e-b19f-c9360685dbf7" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsidiarySaleOfStockAxis_43370f36-531c-4ca3-923f-91ea60542d02" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsidiarySaleOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSubsidiaryOrEquityMethodInvesteeTable_a9d24740-b55f-4d9e-b19f-c9360685dbf7" xlink:to="loc_us-gaap_SubsidiarySaleOfStockAxis_43370f36-531c-4ca3-923f-91ea60542d02" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_43370f36-531c-4ca3-923f-91ea60542d02_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_43370f36-531c-4ca3-923f-91ea60542d02" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_43370f36-531c-4ca3-923f-91ea60542d02_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_db9d41db-4232-4bb7-ba4b-970c8628fee6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_43370f36-531c-4ca3-923f-91ea60542d02" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_db9d41db-4232-4bb7-ba4b-970c8628fee6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IPOMember_bc12afcd-4ff9-4a8c-9b8f-c198cf78281a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IPOMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SaleOfStockNameOfTransactionDomain_db9d41db-4232-4bb7-ba4b-970c8628fee6" xlink:to="loc_us-gaap_IPOMember_bc12afcd-4ff9-4a8c-9b8f-c198cf78281a" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.rackspace.com/role/CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPoliciesCashCashEquivalentsRestrictedCashandPropertyEquipmentandSoftwareandDefiniteLivedIntangibleAssetsDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPoliciesCashCashEquivalentsRestrictedCashandPropertyEquipmentandSoftwareandDefiniteLivedIntangibleAssetsDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPoliciesCashCashEquivalentsRestrictedCashandPropertyEquipmentandSoftwareandDefiniteLivedIntangibleAssetsDetails" xlink:type="extended" id="id0738b440747484d8ccf4bfb4c515dd2_CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPoliciesCashCashEquivalentsRestrictedCashandPropertyEquipmentandSoftwareandDefiniteLivedIntangibleAssetsDetails"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPoliciesEstimatedUsefulLivesDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPoliciesEstimatedUsefulLivesDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPoliciesEstimatedUsefulLivesDetails" xlink:type="extended" id="i333ef1a211cb4b84b6f70d2cb571adbf_CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPoliciesEstimatedUsefulLivesDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_69b4ec7d-0529-4152-a6a2-1664a82c915f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_31087dcd-d8dc-4f3e-b869-8b20ff57dda9" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_69b4ec7d-0529-4152-a6a2-1664a82c915f" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_31087dcd-d8dc-4f3e-b869-8b20ff57dda9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_1bad06de-a60c-476a-bdc2-6cf29cc5c1ff" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_69b4ec7d-0529-4152-a6a2-1664a82c915f" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_1bad06de-a60c-476a-bdc2-6cf29cc5c1ff" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_f485aebe-928e-4469-a9cf-43b6b8037c22" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_1bad06de-a60c-476a-bdc2-6cf29cc5c1ff" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_f485aebe-928e-4469-a9cf-43b6b8037c22" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_f485aebe-928e-4469-a9cf-43b6b8037c22_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_f485aebe-928e-4469-a9cf-43b6b8037c22" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_f485aebe-928e-4469-a9cf-43b6b8037c22_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_b818b985-d643-4cd8-8ad0-a77203c3004a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_f485aebe-928e-4469-a9cf-43b6b8037c22" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_b818b985-d643-4cd8-8ad0-a77203c3004a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_ComputerAndEquipmentMember_e26ef339-94b6-465a-8128-f3ee03aff620" xlink:href="rxt-20201231.xsd#rxt_ComputerAndEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_b818b985-d643-4cd8-8ad0-a77203c3004a" xlink:to="loc_rxt_ComputerAndEquipmentMember_e26ef339-94b6-465a-8128-f3ee03aff620" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SoftwareAndSoftwareDevelopmentCostsMember_02b8fb42-8add-49d4-b493-19dcd54988e8" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SoftwareAndSoftwareDevelopmentCostsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_b818b985-d643-4cd8-8ad0-a77203c3004a" xlink:to="loc_us-gaap_SoftwareAndSoftwareDevelopmentCostsMember_02b8fb42-8add-49d4-b493-19dcd54988e8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FurnitureAndFixturesMember_1b1896a3-dd9a-4cce-b873-c61fd9c8e5c6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FurnitureAndFixturesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_b818b985-d643-4cd8-8ad0-a77203c3004a" xlink:to="loc_us-gaap_FurnitureAndFixturesMember_1b1896a3-dd9a-4cce-b873-c61fd9c8e5c6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_BuildingsAndLeaseholdImprovementsMember_615f11fd-0706-4e0f-84ca-2df37667be8f" xlink:href="rxt-20201231.xsd#rxt_BuildingsAndLeaseholdImprovementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_b818b985-d643-4cd8-8ad0-a77203c3004a" xlink:to="loc_rxt_BuildingsAndLeaseholdImprovementsMember_615f11fd-0706-4e0f-84ca-2df37667be8f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_52106b3d-81ef-4857-8007-deae39c1e83c" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_1bad06de-a60c-476a-bdc2-6cf29cc5c1ff" xlink:to="loc_srt_RangeAxis_52106b3d-81ef-4857-8007-deae39c1e83c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_52106b3d-81ef-4857-8007-deae39c1e83c_default" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_52106b3d-81ef-4857-8007-deae39c1e83c" xlink:to="loc_srt_RangeMember_52106b3d-81ef-4857-8007-deae39c1e83c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_3b33ecda-1772-4bd0-a39c-ae5025a35d37" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_52106b3d-81ef-4857-8007-deae39c1e83c" xlink:to="loc_srt_RangeMember_3b33ecda-1772-4bd0-a39c-ae5025a35d37" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_651d92b3-22ba-4053-bb09-412ee254e8fe" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_3b33ecda-1772-4bd0-a39c-ae5025a35d37" xlink:to="loc_srt_MinimumMember_651d92b3-22ba-4053-bb09-412ee254e8fe" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_a26e6b40-2de5-4d38-84fb-553b2c0e19fe" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_3b33ecda-1772-4bd0-a39c-ae5025a35d37" xlink:to="loc_srt_MaximumMember_a26e6b40-2de5-4d38-84fb-553b2c0e19fe" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.rackspace.com/role/CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPoliciesGoodwillandIntangibleAssetsDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPoliciesGoodwillandIntangibleAssetsDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPoliciesGoodwillandIntangibleAssetsDetails" xlink:type="extended" id="ibf5e8e18a5ad40218da53e096a9bed88_CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPoliciesGoodwillandIntangibleAssetsDetails"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPoliciesLeasesDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPoliciesLeasesDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPoliciesLeasesDetails" xlink:type="extended" id="id407c17313984f23bff384129745319d_CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPoliciesLeasesDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeLeaseDescriptionLineItems_78d9eca6-b363-4c59-99a5-dafa916cd811" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LesseeLeaseDescriptionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_LesseeLeaseTermOfContract_21c9992a-674f-4b44-951a-982784d19bb9" xlink:href="rxt-20201231.xsd#rxt_LesseeLeaseTermOfContract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_78d9eca6-b363-4c59-99a5-dafa916cd811" xlink:to="loc_rxt_LesseeLeaseTermOfContract_21c9992a-674f-4b44-951a-982784d19bb9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseTermOfContract_96fb7311-aec6-4b7d-9436-30eefcacba1d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LesseeOperatingLeaseTermOfContract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_78d9eca6-b363-4c59-99a5-dafa916cd811" xlink:to="loc_us-gaap_LesseeOperatingLeaseTermOfContract_96fb7311-aec6-4b7d-9436-30eefcacba1d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeLeaseDescriptionTable_bc217324-5af8-466d-99e1-1cf41b521c2f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LesseeLeaseDescriptionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_78d9eca6-b363-4c59-99a5-dafa916cd811" xlink:to="loc_us-gaap_LesseeLeaseDescriptionTable_bc217324-5af8-466d-99e1-1cf41b521c2f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_575921ad-6220-4932-9007-061a3e9943fb" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LesseeLeaseDescriptionTable_bc217324-5af8-466d-99e1-1cf41b521c2f" xlink:to="loc_srt_RangeAxis_575921ad-6220-4932-9007-061a3e9943fb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_575921ad-6220-4932-9007-061a3e9943fb_default" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_575921ad-6220-4932-9007-061a3e9943fb" xlink:to="loc_srt_RangeMember_575921ad-6220-4932-9007-061a3e9943fb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_43a11733-e3e3-4132-b843-457c4ab2b15c" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_575921ad-6220-4932-9007-061a3e9943fb" xlink:to="loc_srt_RangeMember_43a11733-e3e3-4132-b843-457c4ab2b15c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_3dfbadff-b01c-4841-acf2-9e6630c91a5e" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_43a11733-e3e3-4132-b843-457c4ab2b15c" xlink:to="loc_srt_MinimumMember_3dfbadff-b01c-4841-acf2-9e6630c91a5e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_9c93d127-6e02-411d-98e4-096aff649b01" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_43a11733-e3e3-4132-b843-457c4ab2b15c" xlink:to="loc_srt_MaximumMember_9c93d127-6e02-411d-98e4-096aff649b01" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_d7925098-4692-41f9-8c11-82bda6800ea1" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LesseeLeaseDescriptionTable_bc217324-5af8-466d-99e1-1cf41b521c2f" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_d7925098-4692-41f9-8c11-82bda6800ea1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_d7925098-4692-41f9-8c11-82bda6800ea1_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_d7925098-4692-41f9-8c11-82bda6800ea1" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_d7925098-4692-41f9-8c11-82bda6800ea1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_e63abc51-c051-4c2d-b992-221359172bbb" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_d7925098-4692-41f9-8c11-82bda6800ea1" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_e63abc51-c051-4c2d-b992-221359172bbb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_DataCentersMember_bca5d938-eb9b-4770-9858-c8dbe411e29d" xlink:href="rxt-20201231.xsd#rxt_DataCentersMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_e63abc51-c051-4c2d-b992-221359172bbb" xlink:to="loc_rxt_DataCentersMember_bca5d938-eb9b-4770-9858-c8dbe411e29d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquipmentMember_32a32504-450e-4021-b35e-c2cb48acbc47" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_e63abc51-c051-4c2d-b992-221359172bbb" xlink:to="loc_us-gaap_EquipmentMember_32a32504-450e-4021-b35e-c2cb48acbc47" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_OfficeSpaceMember_1d47c034-d79d-4df3-8892-c0d366736223" xlink:href="rxt-20201231.xsd#rxt_OfficeSpaceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_e63abc51-c051-4c2d-b992-221359172bbb" xlink:to="loc_rxt_OfficeSpaceMember_1d47c034-d79d-4df3-8892-c0d366736223" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.rackspace.com/role/CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPoliciesRevenueDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPoliciesRevenueDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPoliciesRevenueDetails" xlink:type="extended" id="i3203b60491234ff3a076e5a23a59bd59_CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPoliciesRevenueDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingRevenueReconcilingItemLineItems_148405ff-2ac5-4bf9-8176-94f73cbc661e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SegmentReportingRevenueReconcilingItemLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_RevenueRecognitionCustomerContractPeriodMaximum_2c6369d7-bdd2-4593-aed4-5ac8661253f9" xlink:href="rxt-20201231.xsd#rxt_RevenueRecognitionCustomerContractPeriodMaximum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingRevenueReconcilingItemLineItems_148405ff-2ac5-4bf9-8176-94f73cbc661e" xlink:to="loc_rxt_RevenueRecognitionCustomerContractPeriodMaximum_2c6369d7-bdd2-4593-aed4-5ac8661253f9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_ExpectedServiceDeliveryPeriod_32f3ddd3-bf30-4a26-bc7d-e76250b6089c" xlink:href="rxt-20201231.xsd#rxt_ExpectedServiceDeliveryPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingRevenueReconcilingItemLineItems_148405ff-2ac5-4bf9-8176-94f73cbc661e" xlink:to="loc_rxt_ExpectedServiceDeliveryPeriod_32f3ddd3-bf30-4a26-bc7d-e76250b6089c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReconciliationOfRevenueFromSegmentsToConsolidatedTable_93cb63d6-0303-4718-a96f-872c9f0f10d6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ReconciliationOfRevenueFromSegmentsToConsolidatedTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingRevenueReconcilingItemLineItems_148405ff-2ac5-4bf9-8176-94f73cbc661e" xlink:to="loc_us-gaap_ReconciliationOfRevenueFromSegmentsToConsolidatedTable_93cb63d6-0303-4718-a96f-872c9f0f10d6" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_1e2fcb7a-55d9-44f1-82f8-bd6366d51d75" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ReconciliationOfRevenueFromSegmentsToConsolidatedTable_93cb63d6-0303-4718-a96f-872c9f0f10d6" xlink:to="loc_srt_ProductOrServiceAxis_1e2fcb7a-55d9-44f1-82f8-bd6366d51d75" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_1e2fcb7a-55d9-44f1-82f8-bd6366d51d75_default" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_1e2fcb7a-55d9-44f1-82f8-bd6366d51d75" xlink:to="loc_srt_ProductsAndServicesDomain_1e2fcb7a-55d9-44f1-82f8-bd6366d51d75_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_15dc47a2-5a58-418e-b4d2-02cbecf4704c" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_1e2fcb7a-55d9-44f1-82f8-bd6366d51d75" xlink:to="loc_srt_ProductsAndServicesDomain_15dc47a2-5a58-418e-b4d2-02cbecf4704c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_MultiCloudServicesMember_535c94bf-6687-46e3-8156-de53ddabef0f" xlink:href="rxt-20201231.xsd#rxt_MultiCloudServicesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_15dc47a2-5a58-418e-b4d2-02cbecf4704c" xlink:to="loc_rxt_MultiCloudServicesMember_535c94bf-6687-46e3-8156-de53ddabef0f" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.rackspace.com/role/CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPoliciesSellingGeneralandAdministrativeExpenseandImpairmentLossDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPoliciesSellingGeneralandAdministrativeExpenseandImpairmentLossDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPoliciesSellingGeneralandAdministrativeExpenseandImpairmentLossDetails" xlink:type="extended" id="i0bc1415188104155b824d1e2ca988753_CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPoliciesSellingGeneralandAdministrativeExpenseandImpairmentLossDetails"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPoliciesDerivativeInstrumentsDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPoliciesDerivativeInstrumentsDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPoliciesDerivativeInstrumentsDetails" xlink:type="extended" id="ie75c695c077a4f549df72f0a02183dd5_CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPoliciesDerivativeInstrumentsDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLineItems_e98217a9-25e8-4253-b571-141447b67dc8" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeNumberOfInstrumentsHeld_41ad648f-c442-41cc-9336-baf7b7fd3192" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeNumberOfInstrumentsHeld"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_e98217a9-25e8-4253-b571-141447b67dc8" xlink:to="loc_us-gaap_DerivativeNumberOfInstrumentsHeld_41ad648f-c442-41cc-9336-baf7b7fd3192" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilities_65361482-8a83-4465-b6b3-0d737bac4731" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_e98217a9-25e8-4253-b571-141447b67dc8" xlink:to="loc_us-gaap_DerivativeLiabilities_65361482-8a83-4465-b6b3-0d737bac4731" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeTable_04bd744e-df13-469e-ba3f-23dfd609ceb8" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeLineItems_e98217a9-25e8-4253-b571-141447b67dc8" xlink:to="loc_us-gaap_DerivativeTable_04bd744e-df13-469e-ba3f-23dfd609ceb8" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_f45e83f2-d781-4427-8cd0-098441df90b2" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_04bd744e-df13-469e-ba3f-23dfd609ceb8" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_f45e83f2-d781-4427-8cd0-098441df90b2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_f45e83f2-d781-4427-8cd0-098441df90b2_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_f45e83f2-d781-4427-8cd0-098441df90b2" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_f45e83f2-d781-4427-8cd0-098441df90b2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_f497538d-9b67-4bbf-817d-cfe59a2f8e85" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_f45e83f2-d781-4427-8cd0-098441df90b2" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_f497538d-9b67-4bbf-817d-cfe59a2f8e85" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateSwapMember_920096df-66fb-4fe9-b35c-50c7787f89b5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InterestRateSwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_f497538d-9b67-4bbf-817d-cfe59a2f8e85" xlink:to="loc_us-gaap_InterestRateSwapMember_920096df-66fb-4fe9-b35c-50c7787f89b5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_fcfe46e5-58e5-48a5-b9c7-296110f5d407" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_04bd744e-df13-469e-ba3f-23dfd609ceb8" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_fcfe46e5-58e5-48a5-b9c7-296110f5d407" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingRelationshipDomain_fcfe46e5-58e5-48a5-b9c7-296110f5d407_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_HedgingRelationshipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_fcfe46e5-58e5-48a5-b9c7-296110f5d407" xlink:to="loc_us-gaap_HedgingRelationshipDomain_fcfe46e5-58e5-48a5-b9c7-296110f5d407_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingRelationshipDomain_f3f0cce6-aadf-4ece-808b-06801527fc54" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_HedgingRelationshipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_fcfe46e5-58e5-48a5-b9c7-296110f5d407" xlink:to="loc_us-gaap_HedgingRelationshipDomain_f3f0cce6-aadf-4ece-808b-06801527fc54" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashFlowHedgingMember_b569a3db-60ee-4015-a949-c6fb61c12e09" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CashFlowHedgingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingRelationshipDomain_f3f0cce6-aadf-4ece-808b-06801527fc54" xlink:to="loc_us-gaap_CashFlowHedgingMember_b569a3db-60ee-4015-a949-c6fb61c12e09" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationAxis_ca88e87c-a969-4b2f-a263-6fe594c70ab5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_HedgingDesignationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_04bd744e-df13-469e-ba3f-23dfd609ceb8" xlink:to="loc_us-gaap_HedgingDesignationAxis_ca88e87c-a969-4b2f-a263-6fe594c70ab5" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_ca88e87c-a969-4b2f-a263-6fe594c70ab5_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_ca88e87c-a969-4b2f-a263-6fe594c70ab5" xlink:to="loc_us-gaap_HedgingDesignationDomain_ca88e87c-a969-4b2f-a263-6fe594c70ab5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_5eb5c94c-de5c-4a97-901b-06fca92b236a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_ca88e87c-a969-4b2f-a263-6fe594c70ab5" xlink:to="loc_us-gaap_HedgingDesignationDomain_5eb5c94c-de5c-4a97-901b-06fca92b236a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DesignatedAsHedgingInstrumentMember_c8d46565-1521-4e56-826a-9fe2668200c0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DesignatedAsHedgingInstrumentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_5eb5c94c-de5c-4a97-901b-06fca92b236a" xlink:to="loc_us-gaap_DesignatedAsHedgingInstrumentMember_c8d46565-1521-4e56-826a-9fe2668200c0" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.rackspace.com/role/CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPoliciesSubsequentEventsDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPoliciesSubsequentEventsDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPoliciesSubsequentEventsDetails" xlink:type="extended" id="i4344450848874c77ad0b9b32054c262b_CompanyOverviewBasisofPresentationandSummaryofSignificantAccountingPoliciesSubsequentEventsDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventLineItems_9cc09991-cecb-4729-8303-835dc81b3d2f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsequentEventLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LandAvailableForSale_30c0e38e-904b-488c-a228-0733314308c7" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LandAvailableForSale"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_9cc09991-cecb-4729-8303-835dc81b3d2f" xlink:to="loc_us-gaap_LandAvailableForSale_30c0e38e-904b-488c-a228-0733314308c7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleOfLandHeldForUse_62d7bd7a-f1ce-46ad-ba0b-cb44f8be4bef" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProceedsFromSaleOfLandHeldForUse"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_9cc09991-cecb-4729-8303-835dc81b3d2f" xlink:to="loc_us-gaap_ProceedsFromSaleOfLandHeldForUse_62d7bd7a-f1ce-46ad-ba0b-cb44f8be4bef" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnSaleOfPropertyPlantEquipment_35462e5c-79e0-4417-af3a-8025c1f32fef" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GainLossOnSaleOfPropertyPlantEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_9cc09991-cecb-4729-8303-835dc81b3d2f" xlink:to="loc_us-gaap_GainLossOnSaleOfPropertyPlantEquipment_35462e5c-79e0-4417-af3a-8025c1f32fef" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncashOrPartNoncashAcquisitionNoncashFinancialOrEquityInstrumentConsiderationSharesIssued1_92f4ac18-be08-4a64-9a8a-5925c69e3691" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NoncashOrPartNoncashAcquisitionNoncashFinancialOrEquityInstrumentConsiderationSharesIssued1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_9cc09991-cecb-4729-8303-835dc81b3d2f" xlink:to="loc_us-gaap_NoncashOrPartNoncashAcquisitionNoncashFinancialOrEquityInstrumentConsiderationSharesIssued1_92f4ac18-be08-4a64-9a8a-5925c69e3691" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_eae1c07a-5402-4ad8-b845-c751a01879dd" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_9cc09991-cecb-4729-8303-835dc81b3d2f" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_eae1c07a-5402-4ad8-b845-c751a01879dd" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_40083617-73a2-4cd1-b8fa-3b8294e12ab0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_9cc09991-cecb-4729-8303-835dc81b3d2f" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_40083617-73a2-4cd1-b8fa-3b8294e12ab0" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTerm_f39d9e4d-b0d0-41ad-a2d3-d7cab020d242" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_9cc09991-cecb-4729-8303-835dc81b3d2f" xlink:to="loc_us-gaap_DebtInstrumentTerm_f39d9e4d-b0d0-41ad-a2d3-d7cab020d242" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_84c3810e-b13b-4ccb-a336-d012bb650d8c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_9cc09991-cecb-4729-8303-835dc81b3d2f" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_84c3810e-b13b-4ccb-a336-d012bb650d8c" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_55d4427e-9e84-4682-b29e-c9e0e2137aef" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_9cc09991-cecb-4729-8303-835dc81b3d2f" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_55d4427e-9e84-4682-b29e-c9e0e2137aef" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_DebtInstrumentBasisSpreadOnVariableRateFloor_685a2b9e-a4b5-4f59-9461-b120ea369049" xlink:href="rxt-20201231.xsd#rxt_DebtInstrumentBasisSpreadOnVariableRateFloor"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_9cc09991-cecb-4729-8303-835dc81b3d2f" xlink:to="loc_rxt_DebtInstrumentBasisSpreadOnVariableRateFloor_685a2b9e-a4b5-4f59-9461-b120ea369049" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_430971e7-8316-478b-91de-8ad8d868033d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_9cc09991-cecb-4729-8303-835dc81b3d2f" xlink:to="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_430971e7-8316-478b-91de-8ad8d868033d" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_DebtInstrumentInterestPaymentPeriod_445aad35-c59d-497f-8d8d-265bd30df320" xlink:href="rxt-20201231.xsd#rxt_DebtInstrumentInterestPaymentPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_9cc09991-cecb-4729-8303-835dc81b3d2f" xlink:to="loc_rxt_DebtInstrumentInterestPaymentPeriod_445aad35-c59d-497f-8d8d-265bd30df320" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_DebtInstrumentPeriodicPaymentPercentageOfOriginalPrincipalAmount_8b9b5d0e-1def-41f3-8548-51a3b49611b4" xlink:href="rxt-20201231.xsd#rxt_DebtInstrumentPeriodicPaymentPercentageOfOriginalPrincipalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_9cc09991-cecb-4729-8303-835dc81b3d2f" xlink:to="loc_rxt_DebtInstrumentPeriodicPaymentPercentageOfOriginalPrincipalAmount_8b9b5d0e-1def-41f3-8548-51a3b49611b4" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeNotionalAmount_f14b1458-9f65-425c-901c-bf096c0597e8" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeNotionalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_9cc09991-cecb-4729-8303-835dc81b3d2f" xlink:to="loc_us-gaap_DerivativeNotionalAmount_f14b1458-9f65-425c-901c-bf096c0597e8" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeFixedInterestRate_18617d41-2634-41c4-b7c5-dcf7db02a0d7" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeFixedInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_9cc09991-cecb-4729-8303-835dc81b3d2f" xlink:to="loc_us-gaap_DerivativeFixedInterestRate_18617d41-2634-41c4-b7c5-dcf7db02a0d7" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeVariableInterestRate_60263134-c9de-4aab-a260-8a0aced59d93" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeVariableInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_9cc09991-cecb-4729-8303-835dc81b3d2f" xlink:to="loc_us-gaap_DerivativeVariableInterestRate_60263134-c9de-4aab-a260-8a0aced59d93" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTable_273ed2f8-7e19-4621-a94f-5a54e06a0128" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsequentEventTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SubsequentEventLineItems_9cc09991-cecb-4729-8303-835dc81b3d2f" xlink:to="loc_us-gaap_SubsequentEventTable_273ed2f8-7e19-4621-a94f-5a54e06a0128" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_af778958-68f9-4d43-bf96-e4990d179894" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_273ed2f8-7e19-4621-a94f-5a54e06a0128" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_af778958-68f9-4d43-bf96-e4990d179894" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_af778958-68f9-4d43-bf96-e4990d179894_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_af778958-68f9-4d43-bf96-e4990d179894" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_af778958-68f9-4d43-bf96-e4990d179894_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_389af018-a29c-405e-a510-594fb38234b4" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_af778958-68f9-4d43-bf96-e4990d179894" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_389af018-a29c-405e-a510-594fb38234b4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_41985f6f-4af5-4b02-aea4-e6a47b27ef5f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_389af018-a29c-405e-a510-594fb38234b4" xlink:to="loc_us-gaap_SubsequentEventMember_41985f6f-4af5-4b02-aea4-e6a47b27ef5f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_5620bd29-c58d-4900-b95a-0ef77095e0ee" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_273ed2f8-7e19-4621-a94f-5a54e06a0128" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_5620bd29-c58d-4900-b95a-0ef77095e0ee" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_5620bd29-c58d-4900-b95a-0ef77095e0ee_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_5620bd29-c58d-4900-b95a-0ef77095e0ee" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_5620bd29-c58d-4900-b95a-0ef77095e0ee_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_8af41160-7db9-4ece-8eff-a772071d88bb" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_5620bd29-c58d-4900-b95a-0ef77095e0ee" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_8af41160-7db9-4ece-8eff-a772071d88bb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_DataPipeMember_d1a16bb5-af5c-4d26-8786-056b52ab998f" xlink:href="rxt-20201231.xsd#rxt_DataPipeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_8af41160-7db9-4ece-8eff-a772071d88bb" xlink:to="loc_rxt_DataPipeMember_d1a16bb5-af5c-4d26-8786-056b52ab998f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_26a65c5d-b28f-4ab8-82e6-e49f977ccaf3" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_273ed2f8-7e19-4621-a94f-5a54e06a0128" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_26a65c5d-b28f-4ab8-82e6-e49f977ccaf3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_26a65c5d-b28f-4ab8-82e6-e49f977ccaf3_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_26a65c5d-b28f-4ab8-82e6-e49f977ccaf3" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_26a65c5d-b28f-4ab8-82e6-e49f977ccaf3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_e028190a-c85c-450e-adc3-a32019347ef0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_26a65c5d-b28f-4ab8-82e6-e49f977ccaf3" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_e028190a-c85c-450e-adc3-a32019347ef0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorNotesMember_aa1806b7-a7d3-4dba-bd14-b6bf1e6ebb44" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_e028190a-c85c-450e-adc3-a32019347ef0" xlink:to="loc_us-gaap_SeniorNotesMember_aa1806b7-a7d3-4dba-bd14-b6bf1e6ebb44" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_4bf29d3e-93f8-4d9a-97cb-b7d9168bdcdf" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_e028190a-c85c-450e-adc3-a32019347ef0" xlink:to="loc_us-gaap_LineOfCreditMember_4bf29d3e-93f8-4d9a-97cb-b7d9168bdcdf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebtMember_ae2797c2-ad7c-4183-9872-d52759aa81c9" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_e028190a-c85c-450e-adc3-a32019347ef0" xlink:to="loc_us-gaap_SecuredDebtMember_ae2797c2-ad7c-4183-9872-d52759aa81c9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_c7d61f74-d51e-4ea0-9dac-4d501ad71021" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_273ed2f8-7e19-4621-a94f-5a54e06a0128" xlink:to="loc_us-gaap_DebtInstrumentAxis_c7d61f74-d51e-4ea0-9dac-4d501ad71021" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_c7d61f74-d51e-4ea0-9dac-4d501ad71021_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_c7d61f74-d51e-4ea0-9dac-4d501ad71021" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_c7d61f74-d51e-4ea0-9dac-4d501ad71021_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_4dcfb807-221e-4530-8349-6d432ca49ba6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_c7d61f74-d51e-4ea0-9dac-4d501ad71021" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_4dcfb807-221e-4530-8349-6d432ca49ba6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_A350SeniorSecuredNotesDue2028Member_b3f9a9d7-b903-44a3-af68-c38689d9ca6a" xlink:href="rxt-20201231.xsd#rxt_A350SeniorSecuredNotesDue2028Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_4dcfb807-221e-4530-8349-6d432ca49ba6" xlink:to="loc_rxt_A350SeniorSecuredNotesDue2028Member_b3f9a9d7-b903-44a3-af68-c38689d9ca6a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_FirstLienCreditAgreementMember_7e7d79b8-7760-4cd4-aba3-2d760fd4dc24" xlink:href="rxt-20201231.xsd#rxt_FirstLienCreditAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_4dcfb807-221e-4530-8349-6d432ca49ba6" xlink:to="loc_rxt_FirstLienCreditAgreementMember_7e7d79b8-7760-4cd4-aba3-2d760fd4dc24" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_fc7f7b04-11c6-4a3b-b8f1-c174c0b4a4fd" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_273ed2f8-7e19-4621-a94f-5a54e06a0128" xlink:to="loc_us-gaap_CreditFacilityAxis_fc7f7b04-11c6-4a3b-b8f1-c174c0b4a4fd" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_fc7f7b04-11c6-4a3b-b8f1-c174c0b4a4fd_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_fc7f7b04-11c6-4a3b-b8f1-c174c0b4a4fd" xlink:to="loc_us-gaap_CreditFacilityDomain_fc7f7b04-11c6-4a3b-b8f1-c174c0b4a4fd_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_f37e77a0-a2ba-4982-a802-362691c988db" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_fc7f7b04-11c6-4a3b-b8f1-c174c0b4a4fd" xlink:to="loc_us-gaap_CreditFacilityDomain_f37e77a0-a2ba-4982-a802-362691c988db" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_02b44064-0998-457c-b049-9e635c45dbb4" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_f37e77a0-a2ba-4982-a802-362691c988db" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_02b44064-0998-457c-b049-9e635c45dbb4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateAxis_adb46ed6-3f70-4bd7-8183-d477885ab1c7" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_VariableRateAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_273ed2f8-7e19-4621-a94f-5a54e06a0128" xlink:to="loc_us-gaap_VariableRateAxis_adb46ed6-3f70-4bd7-8183-d477885ab1c7" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_adb46ed6-3f70-4bd7-8183-d477885ab1c7_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VariableRateAxis_adb46ed6-3f70-4bd7-8183-d477885ab1c7" xlink:to="loc_us-gaap_VariableRateDomain_adb46ed6-3f70-4bd7-8183-d477885ab1c7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_58bd2fa8-0697-494f-a304-524ad4116ecb" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VariableRateAxis_adb46ed6-3f70-4bd7-8183-d477885ab1c7" xlink:to="loc_us-gaap_VariableRateDomain_58bd2fa8-0697-494f-a304-524ad4116ecb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LondonInterbankOfferedRateLIBORMember_a995f8aa-ba37-4900-92a5-7c56d4dd7f4d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LondonInterbankOfferedRateLIBORMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_58bd2fa8-0697-494f-a304-524ad4116ecb" xlink:to="loc_us-gaap_LondonInterbankOfferedRateLIBORMember_a995f8aa-ba37-4900-92a5-7c56d4dd7f4d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_FederalFundsRateMember_42b03250-836d-4ba9-aa29-6b3174af6fac" xlink:href="rxt-20201231.xsd#rxt_FederalFundsRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_58bd2fa8-0697-494f-a304-524ad4116ecb" xlink:to="loc_rxt_FederalFundsRateMember_42b03250-836d-4ba9-aa29-6b3174af6fac" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_OneMonthAdjustedLIBORMember_30131c67-267f-4c67-bca2-1022ed574993" xlink:href="rxt-20201231.xsd#rxt_OneMonthAdjustedLIBORMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_58bd2fa8-0697-494f-a304-524ad4116ecb" xlink:to="loc_rxt_OneMonthAdjustedLIBORMember_30131c67-267f-4c67-bca2-1022ed574993" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BaseRateMember_9c94c58a-6291-4a8f-bb55-21dea3040736" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BaseRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_58bd2fa8-0697-494f-a304-524ad4116ecb" xlink:to="loc_us-gaap_BaseRateMember_9c94c58a-6291-4a8f-bb55-21dea3040736" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_16a11c51-8289-45cd-bdc5-e00159527f3b" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_273ed2f8-7e19-4621-a94f-5a54e06a0128" xlink:to="loc_srt_RangeAxis_16a11c51-8289-45cd-bdc5-e00159527f3b" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_16a11c51-8289-45cd-bdc5-e00159527f3b_default" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_16a11c51-8289-45cd-bdc5-e00159527f3b" xlink:to="loc_srt_RangeMember_16a11c51-8289-45cd-bdc5-e00159527f3b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_2da2eb61-bffd-428d-a7f3-6c8e776db9d8" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_16a11c51-8289-45cd-bdc5-e00159527f3b" xlink:to="loc_srt_RangeMember_2da2eb61-bffd-428d-a7f3-6c8e776db9d8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_d72bfa22-a4c6-414d-a6de-11ff4e40afa5" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_2da2eb61-bffd-428d-a7f3-6c8e776db9d8" xlink:to="loc_srt_MaximumMember_d72bfa22-a4c6-414d-a6de-11ff4e40afa5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_85e6c4e4-7f8e-4e60-9b0f-447901cacd4c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_273ed2f8-7e19-4621-a94f-5a54e06a0128" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_85e6c4e4-7f8e-4e60-9b0f-447901cacd4c" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_85e6c4e4-7f8e-4e60-9b0f-447901cacd4c_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_85e6c4e4-7f8e-4e60-9b0f-447901cacd4c" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_85e6c4e4-7f8e-4e60-9b0f-447901cacd4c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_bb91ad30-df6d-4e22-82c8-a7ac50a86654" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_85e6c4e4-7f8e-4e60-9b0f-447901cacd4c" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_bb91ad30-df6d-4e22-82c8-a7ac50a86654" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateSwapMember_bcba6f43-e675-4e4a-878f-5fd34f5cdccd" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InterestRateSwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_bb91ad30-df6d-4e22-82c8-a7ac50a86654" xlink:to="loc_us-gaap_InterestRateSwapMember_bcba6f43-e675-4e4a-878f-5fd34f5cdccd" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.rackspace.com/role/CustomerContracts" xlink:type="simple" xlink:href="rxt-20201231.xsd#CustomerContracts"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/CustomerContracts" xlink:type="extended" id="i782007b30ef24883b501b38d2b647452_CustomerContracts"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/CustomerContractsTables" xlink:type="simple" xlink:href="rxt-20201231.xsd#CustomerContractsTables"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/CustomerContractsTables" xlink:type="extended" id="ibec3df7120fc429587df9762e443ab7a_CustomerContractsTables"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/CustomerContractsScheduleofBalancesRelatedtoCustomerContractsDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#CustomerContractsScheduleofBalancesRelatedtoCustomerContractsDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/CustomerContractsScheduleofBalancesRelatedtoCustomerContractsDetails" xlink:type="extended" id="i8ab95aa5b69f4e8f897897364aa119a3_CustomerContractsScheduleofBalancesRelatedtoCustomerContractsDetails"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/CustomerContractsAllowanceforDoubtfulAccountsDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#CustomerContractsAllowanceforDoubtfulAccountsDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/CustomerContractsAllowanceforDoubtfulAccountsDetails" xlink:type="extended" id="i4224739c904a4542beae9b71d9a5e6aa_CustomerContractsAllowanceforDoubtfulAccountsDetails"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/CustomerContractsNarrativeDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#CustomerContractsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/CustomerContractsNarrativeDetails" xlink:type="extended" id="ic2467a97c8e7467195604edf0bbb56f8_CustomerContractsNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizedContractCostLineItems_7385d3d8-6e0c-4eac-b817-7e42e1d377d7" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CapitalizedContractCostLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityRevenueRecognized_05ebee17-b399-47f7-8e38-872373ad4031" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ContractWithCustomerLiabilityRevenueRecognized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CapitalizedContractCostLineItems_7385d3d8-6e0c-4eac-b817-7e42e1d377d7" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityRevenueRecognized_05ebee17-b399-47f7-8e38-872373ad4031" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizedContractCostNet_5d746541-64a3-488d-b2fb-19b34a7c10a8" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CapitalizedContractCostNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CapitalizedContractCostLineItems_7385d3d8-6e0c-4eac-b817-7e42e1d377d7" xlink:to="loc_us-gaap_CapitalizedContractCostNet_5d746541-64a3-488d-b2fb-19b34a7c10a8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizedContractCostTable_8d2577bb-dd2b-434d-a79e-5ae6c6c5ec15" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CapitalizedContractCostTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_CapitalizedContractCostLineItems_7385d3d8-6e0c-4eac-b817-7e42e1d377d7" xlink:to="loc_us-gaap_CapitalizedContractCostTable_8d2577bb-dd2b-434d-a79e-5ae6c6c5ec15" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizedContractCostAxis_5ccaf205-deb9-4e66-aea0-015c2de26e3e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CapitalizedContractCostAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_CapitalizedContractCostTable_8d2577bb-dd2b-434d-a79e-5ae6c6c5ec15" xlink:to="loc_us-gaap_CapitalizedContractCostAxis_5ccaf205-deb9-4e66-aea0-015c2de26e3e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizedContractCostDomain_5ccaf205-deb9-4e66-aea0-015c2de26e3e_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CapitalizedContractCostDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CapitalizedContractCostAxis_5ccaf205-deb9-4e66-aea0-015c2de26e3e" xlink:to="loc_us-gaap_CapitalizedContractCostDomain_5ccaf205-deb9-4e66-aea0-015c2de26e3e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizedContractCostDomain_9e980e71-7c0a-4801-87ad-d769af2dcf1d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CapitalizedContractCostDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CapitalizedContractCostAxis_5ccaf205-deb9-4e66-aea0-015c2de26e3e" xlink:to="loc_us-gaap_CapitalizedContractCostDomain_9e980e71-7c0a-4801-87ad-d769af2dcf1d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_CostToObtainAContractMember_1d55f281-857b-49eb-bab7-0c02b2c35e01" xlink:href="rxt-20201231.xsd#rxt_CostToObtainAContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CapitalizedContractCostDomain_9e980e71-7c0a-4801-87ad-d769af2dcf1d" xlink:to="loc_rxt_CostToObtainAContractMember_1d55f281-857b-49eb-bab7-0c02b2c35e01" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_CostToFulfillAContractMember_66536a60-c5e9-44bc-aa80-514219624377" xlink:href="rxt-20201231.xsd#rxt_CostToFulfillAContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CapitalizedContractCostDomain_9e980e71-7c0a-4801-87ad-d769af2dcf1d" xlink:to="loc_rxt_CostToFulfillAContractMember_66536a60-c5e9-44bc-aa80-514219624377" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.rackspace.com/role/CustomerContractsScheduleofAmortizationofCapitalizedContractCostsDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#CustomerContractsScheduleofAmortizationofCapitalizedContractCostsDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/CustomerContractsScheduleofAmortizationofCapitalizedContractCostsDetails" xlink:type="extended" id="idd9dc4cb26d6494687a527203efae06a_CustomerContractsScheduleofAmortizationofCapitalizedContractCostsDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizedContractCostLineItems_7c3fd5ef-25ce-49c3-9b85-9c4d1cade46e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CapitalizedContractCostLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizedContractCostAmortization_6a906d23-bcaf-4dfa-89bc-82c83e263b0e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CapitalizedContractCostAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CapitalizedContractCostLineItems_7c3fd5ef-25ce-49c3-9b85-9c4d1cade46e" xlink:to="loc_us-gaap_CapitalizedContractCostAmortization_6a906d23-bcaf-4dfa-89bc-82c83e263b0e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizedContractCostTable_54e191fe-7465-4948-a7fa-19acb36f4a1e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CapitalizedContractCostTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_CapitalizedContractCostLineItems_7c3fd5ef-25ce-49c3-9b85-9c4d1cade46e" xlink:to="loc_us-gaap_CapitalizedContractCostTable_54e191fe-7465-4948-a7fa-19acb36f4a1e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizedContractCostAxis_a954ee22-cdcc-4a65-b7ea-dc794e7fbfdb" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CapitalizedContractCostAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_CapitalizedContractCostTable_54e191fe-7465-4948-a7fa-19acb36f4a1e" xlink:to="loc_us-gaap_CapitalizedContractCostAxis_a954ee22-cdcc-4a65-b7ea-dc794e7fbfdb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizedContractCostDomain_a954ee22-cdcc-4a65-b7ea-dc794e7fbfdb_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CapitalizedContractCostDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CapitalizedContractCostAxis_a954ee22-cdcc-4a65-b7ea-dc794e7fbfdb" xlink:to="loc_us-gaap_CapitalizedContractCostDomain_a954ee22-cdcc-4a65-b7ea-dc794e7fbfdb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizedContractCostDomain_80b1e1cf-617c-4147-9fe6-64e1d5b9e0d0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CapitalizedContractCostDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CapitalizedContractCostAxis_a954ee22-cdcc-4a65-b7ea-dc794e7fbfdb" xlink:to="loc_us-gaap_CapitalizedContractCostDomain_80b1e1cf-617c-4147-9fe6-64e1d5b9e0d0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_SalesCommissionsMember_d850e509-1913-42e8-82b5-34eb1ade69b6" xlink:href="rxt-20201231.xsd#rxt_SalesCommissionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CapitalizedContractCostDomain_80b1e1cf-617c-4147-9fe6-64e1d5b9e0d0" xlink:to="loc_rxt_SalesCommissionsMember_d850e509-1913-42e8-82b5-34eb1ade69b6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_ImplementationCostsMember_65409abf-2884-4ee4-88af-0001c8ab2b01" xlink:href="rxt-20201231.xsd#rxt_ImplementationCostsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CapitalizedContractCostDomain_80b1e1cf-617c-4147-9fe6-64e1d5b9e0d0" xlink:to="loc_rxt_ImplementationCostsMember_65409abf-2884-4ee4-88af-0001c8ab2b01" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.rackspace.com/role/CustomerContractsRemainingPerformanceObligationsDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#CustomerContractsRemainingPerformanceObligationsDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/CustomerContractsRemainingPerformanceObligationsDetails" xlink:type="extended" id="i4d54378847984aa18859d6e52bf9bb8c_CustomerContractsRemainingPerformanceObligationsDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_ecbe0041-26ea-45a7-8470-d5b4c0670f24" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligation_7656c44e-13dd-4a6c-8ffb-b65eb4ada4ea" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_ecbe0041-26ea-45a7-8470-d5b4c0670f24" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligation_7656c44e-13dd-4a6c-8ffb-b65eb4ada4ea" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_bc0e6a6c-ae49-46ba-9d5e-23fec60a2a08" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_ecbe0041-26ea-45a7-8470-d5b4c0670f24" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_bc0e6a6c-ae49-46ba-9d5e-23fec60a2a08" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_4473b525-c6c6-4f41-b942-5987a948e682" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_ecbe0041-26ea-45a7-8470-d5b4c0670f24" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_4473b525-c6c6-4f41-b942-5987a948e682" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_46ede1d0-49c2-4710-9940-564069a0ad15" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_ecbe0041-26ea-45a7-8470-d5b4c0670f24" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_46ede1d0-49c2-4710-9940-564069a0ad15" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_6eb39115-7b9b-43e4-af8a-692628cd9f86" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_46ede1d0-49c2-4710-9940-564069a0ad15" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_6eb39115-7b9b-43e4-af8a-692628cd9f86" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.rackspace.com/role/CustomerContractsRemainingPerformanceObligationsDetails_1" xlink:type="simple" xlink:href="rxt-20201231.xsd#CustomerContractsRemainingPerformanceObligationsDetails_1"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/CustomerContractsRemainingPerformanceObligationsDetails_1" xlink:type="extended" id="i249393cb8f05484d86f01b88692a01ee_CustomerContractsRemainingPerformanceObligationsDetails_1">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_ecbe0041-26ea-45a7-8470-d5b4c0670f24" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligation_7656c44e-13dd-4a6c-8ffb-b65eb4ada4ea" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_ecbe0041-26ea-45a7-8470-d5b4c0670f24" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligation_7656c44e-13dd-4a6c-8ffb-b65eb4ada4ea" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_bc0e6a6c-ae49-46ba-9d5e-23fec60a2a08" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_ecbe0041-26ea-45a7-8470-d5b4c0670f24" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_bc0e6a6c-ae49-46ba-9d5e-23fec60a2a08" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_4473b525-c6c6-4f41-b942-5987a948e682" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_ecbe0041-26ea-45a7-8470-d5b4c0670f24" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_4473b525-c6c6-4f41-b942-5987a948e682" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_46ede1d0-49c2-4710-9940-564069a0ad15" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_ecbe0041-26ea-45a7-8470-d5b4c0670f24" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_46ede1d0-49c2-4710-9940-564069a0ad15" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.rackspace.com/role/NetLossPerShare" xlink:type="simple" xlink:href="rxt-20201231.xsd#NetLossPerShare"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/NetLossPerShare" xlink:type="extended" id="i6e0a0c3c3b8941a4b3ab4ab881cc72a1_NetLossPerShare"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/NetLossPerShareTables" xlink:type="simple" xlink:href="rxt-20201231.xsd#NetLossPerShareTables"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/NetLossPerShareTables" xlink:type="extended" id="i3049839be5fc4d58b31232e8d3822672_NetLossPerShareTables"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/NetLossPerShareComputationofBasicandDilutedNetIncomeLossperShareDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#NetLossPerShareComputationofBasicandDilutedNetIncomeLossperShareDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/NetLossPerShareComputationofBasicandDilutedNetIncomeLossperShareDetails" xlink:type="extended" id="ia5fad81b88224a64a5dfc54035395db1_NetLossPerShareComputationofBasicandDilutedNetIncomeLossperShareDetails"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/NetLossPerShareNarrativeDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#NetLossPerShareNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/NetLossPerShareNarrativeDetails" xlink:type="extended" id="ic7c704f653e04d819f809f682060199a_NetLossPerShareNarrativeDetails"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/PropertyEquipmentandSoftwarenet" xlink:type="simple" xlink:href="rxt-20201231.xsd#PropertyEquipmentandSoftwarenet"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/PropertyEquipmentandSoftwarenet" xlink:type="extended" id="ifaceec061a434725a407d5e3881f846a_PropertyEquipmentandSoftwarenet"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/PropertyEquipmentandSoftwarenetTables" xlink:type="simple" xlink:href="rxt-20201231.xsd#PropertyEquipmentandSoftwarenetTables"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/PropertyEquipmentandSoftwarenetTables" xlink:type="extended" id="id168b282472a47d2b20472d29df8f157_PropertyEquipmentandSoftwarenetTables"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/PropertyEquipmentandSoftwarenetScheduleofPropertyEquipmentandSoftwarenetDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#PropertyEquipmentandSoftwarenetScheduleofPropertyEquipmentandSoftwarenetDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/PropertyEquipmentandSoftwarenetScheduleofPropertyEquipmentandSoftwarenetDetails" xlink:type="extended" id="i4f1d653150d0445f9309539ab9d6ff32_PropertyEquipmentandSoftwarenetScheduleofPropertyEquipmentandSoftwarenetDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_4e281e78-9600-4b7f-a8f0-6051067b4538" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetBeforeAccumulatedDepreciationAndAmortizationExcludingConstructionInProgress_f3cc0d99-14b5-47ff-9af3-b796d4fe5582" xlink:href="rxt-20201231.xsd#rxt_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetBeforeAccumulatedDepreciationAndAmortizationExcludingConstructionInProgress"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_4e281e78-9600-4b7f-a8f0-6051067b4538" xlink:to="loc_rxt_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetBeforeAccumulatedDepreciationAndAmortizationExcludingConstructionInProgress_f3cc0d99-14b5-47ff-9af3-b796d4fe5582" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAccumulatedDepreciationAndAmortization_6da15422-1a5e-4ef4-86c8-ffd34539c176" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAccumulatedDepreciationAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_4e281e78-9600-4b7f-a8f0-6051067b4538" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAccumulatedDepreciationAndAmortization_6da15422-1a5e-4ef4-86c8-ffd34539c176" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetBeforeAccumulatedDepreciationAndAmortization_fbe145df-4647-4092-85d2-fef5681e338a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetBeforeAccumulatedDepreciationAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_4e281e78-9600-4b7f-a8f0-6051067b4538" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetBeforeAccumulatedDepreciationAndAmortization_fbe145df-4647-4092-85d2-fef5681e338a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization_176f016b-00ed-4e7b-abec-b7f14ad82400" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_4e281e78-9600-4b7f-a8f0-6051067b4538" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization_176f016b-00ed-4e7b-abec-b7f14ad82400" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_14046cf3-7e11-40b1-a7f9-b6403c51267e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_4e281e78-9600-4b7f-a8f0-6051067b4538" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_14046cf3-7e11-40b1-a7f9-b6403c51267e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_37a32a16-064d-4ed8-b420-778288ca2f72" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_14046cf3-7e11-40b1-a7f9-b6403c51267e" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_37a32a16-064d-4ed8-b420-778288ca2f72" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_37a32a16-064d-4ed8-b420-778288ca2f72_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_37a32a16-064d-4ed8-b420-778288ca2f72" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_37a32a16-064d-4ed8-b420-778288ca2f72_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_909997ec-c7bb-4e46-bd4e-0a030e4cd917" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_37a32a16-064d-4ed8-b420-778288ca2f72" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_909997ec-c7bb-4e46-bd4e-0a030e4cd917" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_ComputerAndEquipmentMember_1af0d607-54c9-416d-97e8-d8ec8cc0ef8a" xlink:href="rxt-20201231.xsd#rxt_ComputerAndEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_909997ec-c7bb-4e46-bd4e-0a030e4cd917" xlink:to="loc_rxt_ComputerAndEquipmentMember_1af0d607-54c9-416d-97e8-d8ec8cc0ef8a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SoftwareAndSoftwareDevelopmentCostsMember_ae853a48-c470-431a-8865-56ff8455d8a0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SoftwareAndSoftwareDevelopmentCostsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_909997ec-c7bb-4e46-bd4e-0a030e4cd917" xlink:to="loc_us-gaap_SoftwareAndSoftwareDevelopmentCostsMember_ae853a48-c470-431a-8865-56ff8455d8a0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FurnitureAndFixturesMember_1bff1d3e-a492-4132-80fc-59a3fdbb1786" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FurnitureAndFixturesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_909997ec-c7bb-4e46-bd4e-0a030e4cd917" xlink:to="loc_us-gaap_FurnitureAndFixturesMember_1bff1d3e-a492-4132-80fc-59a3fdbb1786" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_BuildingsAndLeaseholdImprovementsMember_499358c4-014f-4134-bf77-2a81a6240948" xlink:href="rxt-20201231.xsd#rxt_BuildingsAndLeaseholdImprovementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_909997ec-c7bb-4e46-bd4e-0a030e4cd917" xlink:to="loc_rxt_BuildingsAndLeaseholdImprovementsMember_499358c4-014f-4134-bf77-2a81a6240948" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LandMember_261e3f8a-6213-4ff4-9606-d7e4bd55a4ef" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LandMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_909997ec-c7bb-4e46-bd4e-0a030e4cd917" xlink:to="loc_us-gaap_LandMember_261e3f8a-6213-4ff4-9606-d7e4bd55a4ef" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConstructionInProgressMember_f994effc-c0e4-4f46-8a77-a2dd9d45788c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ConstructionInProgressMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_909997ec-c7bb-4e46-bd4e-0a030e4cd917" xlink:to="loc_us-gaap_ConstructionInProgressMember_f994effc-c0e4-4f46-8a77-a2dd9d45788c" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.rackspace.com/role/PropertyEquipmentandSoftwarenetNarrativeDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#PropertyEquipmentandSoftwarenetNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/PropertyEquipmentandSoftwarenetNarrativeDetails" xlink:type="extended" id="ib5e561bbcf9a4a7789d7eab2e8671844_PropertyEquipmentandSoftwarenetNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_2a68fae7-efb8-4800-b43b-952fa5815c41" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Depreciation_d2d6b6b2-547a-4751-80d4-baaf06f4771c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Depreciation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_2a68fae7-efb8-4800-b43b-952fa5815c41" xlink:to="loc_us-gaap_Depreciation_d2d6b6b2-547a-4751-80d4-baaf06f4771c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_AcceleratedDepreciationRevisionOfUsefulLifeEstimates_ed03b1e1-fa62-463d-826b-b4e278eec751" xlink:href="rxt-20201231.xsd#rxt_AcceleratedDepreciationRevisionOfUsefulLifeEstimates"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_2a68fae7-efb8-4800-b43b-952fa5815c41" xlink:to="loc_rxt_AcceleratedDepreciationRevisionOfUsefulLifeEstimates_ed03b1e1-fa62-463d-826b-b4e278eec751" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_5eb4fdb8-97f7-4416-b6c1-f9d35a6bda00" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_2a68fae7-efb8-4800-b43b-952fa5815c41" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_5eb4fdb8-97f7-4416-b6c1-f9d35a6bda00" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByAssetClassAxis_33bcc4df-d68c-4af8-b3d9-f4ea8e5f4123" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueByAssetClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_5eb4fdb8-97f7-4416-b6c1-f9d35a6bda00" xlink:to="loc_us-gaap_FairValueByAssetClassAxis_33bcc4df-d68c-4af8-b3d9-f4ea8e5f4123" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_33bcc4df-d68c-4af8-b3d9-f4ea8e5f4123_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_33bcc4df-d68c-4af8-b3d9-f4ea8e5f4123" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_33bcc4df-d68c-4af8-b3d9-f4ea8e5f4123_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_dba7f0be-39b6-4072-a54e-f65976b23d7d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_33bcc4df-d68c-4af8-b3d9-f4ea8e5f4123" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_dba7f0be-39b6-4072-a54e-f65976b23d7d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetMember_fb383869-d7eb-4306-aa65-fc89624d436c" xlink:href="rxt-20201231.xsd#rxt_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_dba7f0be-39b6-4072-a54e-f65976b23d7d" xlink:to="loc_rxt_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetMember_fb383869-d7eb-4306-aa65-fc89624d436c" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.rackspace.com/role/GoodwillandIntangibleAssets" xlink:type="simple" xlink:href="rxt-20201231.xsd#GoodwillandIntangibleAssets"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/GoodwillandIntangibleAssets" xlink:type="extended" id="i14e10b997b074273b23a349189f3fc99_GoodwillandIntangibleAssets"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/GoodwillandIntangibleAssetsTables" xlink:type="simple" xlink:href="rxt-20201231.xsd#GoodwillandIntangibleAssetsTables"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/GoodwillandIntangibleAssetsTables" xlink:type="extended" id="ic070361ff3994a51a61093a30bf27dd5_GoodwillandIntangibleAssetsTables"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/GoodwillandIntangibleAssetsChangesinCarryingAmountsofGoodwillbyReportableSegmentDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#GoodwillandIntangibleAssetsChangesinCarryingAmountsofGoodwillbyReportableSegmentDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/GoodwillandIntangibleAssetsChangesinCarryingAmountsofGoodwillbyReportableSegmentDetails" xlink:type="extended" id="ifb24e3b9d8b445799de1678f559ff79a_GoodwillandIntangibleAssetsChangesinCarryingAmountsofGoodwillbyReportableSegmentDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillLineItems_ca7389e4-294e-4f15-a5eb-03a3630afde2" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GoodwillLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillRollForward_c8fe51ee-5c58-44a1-aeea-f8bd61843694" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GoodwillRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_ca7389e4-294e-4f15-a5eb-03a3630afde2" xlink:to="loc_us-gaap_GoodwillRollForward_c8fe51ee-5c58-44a1-aeea-f8bd61843694" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_d6974e84-c43a-417c-ab9c-2589c16fb6f4" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_c8fe51ee-5c58-44a1-aeea-f8bd61843694" xlink:to="loc_us-gaap_Goodwill_d6974e84-c43a-417c-ab9c-2589c16fb6f4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillAcquiredDuringPeriod_782ec2d2-ae66-4ef0-9fd0-26ded74cd0e3" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GoodwillAcquiredDuringPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_c8fe51ee-5c58-44a1-aeea-f8bd61843694" xlink:to="loc_us-gaap_GoodwillAcquiredDuringPeriod_782ec2d2-ae66-4ef0-9fd0-26ded74cd0e3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillForeignCurrencyTranslationGainLoss_a991bded-e09f-4790-bde7-43d75e7e0c30" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GoodwillForeignCurrencyTranslationGainLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_c8fe51ee-5c58-44a1-aeea-f8bd61843694" xlink:to="loc_us-gaap_GoodwillForeignCurrencyTranslationGainLoss_a991bded-e09f-4790-bde7-43d75e7e0c30" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillPurchaseAccountingAdjustments_7e0f2f5f-11f5-49ff-81e2-cc1d4e83462b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GoodwillPurchaseAccountingAdjustments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_c8fe51ee-5c58-44a1-aeea-f8bd61843694" xlink:to="loc_us-gaap_GoodwillPurchaseAccountingAdjustments_7e0f2f5f-11f5-49ff-81e2-cc1d4e83462b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_b0a496a4-340c-4d71-b3e5-fa926b94c612" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Goodwill"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillGross_386960c9-3d28-4603-a2a0-fb05ccae8420" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GoodwillGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_ca7389e4-294e-4f15-a5eb-03a3630afde2" xlink:to="loc_us-gaap_GoodwillGross_386960c9-3d28-4603-a2a0-fb05ccae8420" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillImpairedAccumulatedImpairmentLoss_15724362-82a1-4ee9-80ec-162c204b8fb1" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GoodwillImpairedAccumulatedImpairmentLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_ca7389e4-294e-4f15-a5eb-03a3630afde2" xlink:to="loc_us-gaap_GoodwillImpairedAccumulatedImpairmentLoss_15724362-82a1-4ee9-80ec-162c204b8fb1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_e375f1fd-8fcd-4131-9d63-ac8364d289cd" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Goodwill"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfGoodwillTable_4009b3e1-4029-46aa-9d44-f86ecb486304" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfGoodwillTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_GoodwillLineItems_ca7389e4-294e-4f15-a5eb-03a3630afde2" xlink:to="loc_us-gaap_ScheduleOfGoodwillTable_4009b3e1-4029-46aa-9d44-f86ecb486304" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_7c03fda5-6443-4d16-a60d-cdc181aba29b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfGoodwillTable_4009b3e1-4029-46aa-9d44-f86ecb486304" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_7c03fda5-6443-4d16-a60d-cdc181aba29b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_7c03fda5-6443-4d16-a60d-cdc181aba29b_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_7c03fda5-6443-4d16-a60d-cdc181aba29b" xlink:to="loc_us-gaap_SegmentDomain_7c03fda5-6443-4d16-a60d-cdc181aba29b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_09ba576f-24e2-46d7-afed-e41df1c007b5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_7c03fda5-6443-4d16-a60d-cdc181aba29b" xlink:to="loc_us-gaap_SegmentDomain_09ba576f-24e2-46d7-afed-e41df1c007b5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_MultiCloudServicesSegmentMember_9b781a4c-a51c-4fde-a27a-c55ac4ee986a" xlink:href="rxt-20201231.xsd#rxt_MultiCloudServicesSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_09ba576f-24e2-46d7-afed-e41df1c007b5" xlink:to="loc_rxt_MultiCloudServicesSegmentMember_9b781a4c-a51c-4fde-a27a-c55ac4ee986a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_AppsCrossPlatformSegmentMember_5359582a-abf1-4739-a9f8-e5fce70ae0bf" xlink:href="rxt-20201231.xsd#rxt_AppsCrossPlatformSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_09ba576f-24e2-46d7-afed-e41df1c007b5" xlink:to="loc_rxt_AppsCrossPlatformSegmentMember_5359582a-abf1-4739-a9f8-e5fce70ae0bf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_OpenStackPublicCloudSegmentMember_422f2f32-bb94-4c25-b2be-42d193ab69b6" xlink:href="rxt-20201231.xsd#rxt_OpenStackPublicCloudSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_09ba576f-24e2-46d7-afed-e41df1c007b5" xlink:to="loc_rxt_OpenStackPublicCloudSegmentMember_422f2f32-bb94-4c25-b2be-42d193ab69b6" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.rackspace.com/role/GoodwillandIntangibleAssetsIntangibleAssetsOtherThanGoodwillDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#GoodwillandIntangibleAssetsIntangibleAssetsOtherThanGoodwillDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/GoodwillandIntangibleAssetsIntangibleAssetsOtherThanGoodwillDetails" xlink:type="extended" id="i66cd4f00f47c44faa695004edf777274_GoodwillandIntangibleAssetsIntangibleAssetsOtherThanGoodwillDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_2b2b2858-9d23-4e67-8053-48d8ea832ee8" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_33a610b0-7627-4094-8612-efc4a0376da1" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_2b2b2858-9d23-4e67-8053-48d8ea832ee8" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_33a610b0-7627-4094-8612-efc4a0376da1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_345f0c2c-5af9-4b2d-82cc-1291c517c908" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_2b2b2858-9d23-4e67-8053-48d8ea832ee8" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_345f0c2c-5af9-4b2d-82cc-1291c517c908" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_d021b1d5-104b-47bc-9aa7-beed4dcde8d1" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_2b2b2858-9d23-4e67-8053-48d8ea832ee8" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_d021b1d5-104b-47bc-9aa7-beed4dcde8d1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_52fbc9a3-74f9-4ff7-a137-55a0f60bdaad" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_2b2b2858-9d23-4e67-8053-48d8ea832ee8" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_52fbc9a3-74f9-4ff7-a137-55a0f60bdaad" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_20b0bf49-1e42-49c0-a03b-4f7629ef80b6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_52fbc9a3-74f9-4ff7-a137-55a0f60bdaad" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_20b0bf49-1e42-49c0-a03b-4f7629ef80b6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_20b0bf49-1e42-49c0-a03b-4f7629ef80b6_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_20b0bf49-1e42-49c0-a03b-4f7629ef80b6" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_20b0bf49-1e42-49c0-a03b-4f7629ef80b6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_d4b976f6-81c2-452a-8e70-0229009e86d6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_20b0bf49-1e42-49c0-a03b-4f7629ef80b6" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_d4b976f6-81c2-452a-8e70-0229009e86d6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelationshipsMember_4a33b61b-652e-4527-92a6-8a02b81d8c1d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CustomerRelationshipsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_d4b976f6-81c2-452a-8e70-0229009e86d6" xlink:to="loc_us-gaap_CustomerRelationshipsMember_4a33b61b-652e-4527-92a6-8a02b81d8c1d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_PropertyTaxAbatementMember_9efffb1e-f125-45c7-b455-0db794e797a8" xlink:href="rxt-20201231.xsd#rxt_PropertyTaxAbatementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_d4b976f6-81c2-452a-8e70-0229009e86d6" xlink:to="loc_rxt_PropertyTaxAbatementMember_9efffb1e-f125-45c7-b455-0db794e797a8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherIntangibleAssetsMember_864dd071-0041-44d1-8fc9-ce8698792aa0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherIntangibleAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_d4b976f6-81c2-452a-8e70-0229009e86d6" xlink:to="loc_us-gaap_OtherIntangibleAssetsMember_864dd071-0041-44d1-8fc9-ce8698792aa0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassLineItems_8344c57c-37df-4947-8c47-141dcc6fb600" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_0f48eef5-6c97-4f75-a79f-e5c9dd549bb6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassLineItems_8344c57c-37df-4947-8c47-141dcc6fb600" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_0f48eef5-6c97-4f75-a79f-e5c9dd549bb6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfIndefiniteLivedIntangibleAssetsTable_0933f33c-b4be-4778-8168-a950fdd16833" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfIndefiniteLivedIntangibleAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassLineItems_8344c57c-37df-4947-8c47-141dcc6fb600" xlink:to="loc_us-gaap_ScheduleOfIndefiniteLivedIntangibleAssetsTable_0933f33c-b4be-4778-8168-a950fdd16833" xlink:type="arc" order="2" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_820f3297-3402-480f-a617-43276c159d43" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfIndefiniteLivedIntangibleAssetsTable_0933f33c-b4be-4778-8168-a950fdd16833" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_820f3297-3402-480f-a617-43276c159d43" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_820f3297-3402-480f-a617-43276c159d43_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_820f3297-3402-480f-a617-43276c159d43" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_820f3297-3402-480f-a617-43276c159d43_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_b8c47d18-ea50-4e1d-bcb6-54dd6f9aff46" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_820f3297-3402-480f-a617-43276c159d43" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_b8c47d18-ea50-4e1d-bcb6-54dd6f9aff46" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradeNamesMember_c5457b5b-ad81-4fe0-9db2-5e977e150e24" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TradeNamesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_b8c47d18-ea50-4e1d-bcb6-54dd6f9aff46" xlink:to="loc_us-gaap_TradeNamesMember_c5457b5b-ad81-4fe0-9db2-5e977e150e24" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.rackspace.com/role/GoodwillandIntangibleAssetsNarrativeDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#GoodwillandIntangibleAssetsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/GoodwillandIntangibleAssetsNarrativeDetails" xlink:type="extended" id="iaf36da2a14814d97a03379c78969cbbd_GoodwillandIntangibleAssetsNarrativeDetails"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/GoodwillandIntangibleAssetsFutureAmortizationofIntangibleAssetsDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#GoodwillandIntangibleAssetsFutureAmortizationofIntangibleAssetsDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/GoodwillandIntangibleAssetsFutureAmortizationofIntangibleAssetsDetails" xlink:type="extended" id="ib775bc3402254f549257615c5fa5f2d5_GoodwillandIntangibleAssetsFutureAmortizationofIntangibleAssetsDetails"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/Investments" xlink:type="simple" xlink:href="rxt-20201231.xsd#Investments"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/Investments" xlink:type="extended" id="i1684ceb1931547bca6dcc511b11427d4_Investments"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/InvestmentsNarrativeDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#InvestmentsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/InvestmentsNarrativeDetails" xlink:type="extended" id="ic3204e47243247e78d9ce2c99d38b4b6_InvestmentsNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_765e149b-d987-4f2e-bc62-f11735fdde04" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfEquityMethodInvestmentsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueAmount_ce8cd0a0-55f0-4415-b0f4-33204ef7bbcf" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_765e149b-d987-4f2e-bc62-f11735fdde04" xlink:to="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueAmount_ce8cd0a0-55f0-4415-b0f4-33204ef7bbcf" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleMaturityAndCollectionsOfInvestments_d0bf8b14-9401-4097-983b-c0b2ae86b7d9" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProceedsFromSaleMaturityAndCollectionsOfInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_765e149b-d987-4f2e-bc62-f11735fdde04" xlink:to="loc_us-gaap_ProceedsFromSaleMaturityAndCollectionsOfInvestments_d0bf8b14-9401-4097-983b-c0b2ae86b7d9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnInvestments_5374c51d-bd4c-4c1a-9f95-164ef8fb15ef" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GainLossOnInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_765e149b-d987-4f2e-bc62-f11735fdde04" xlink:to="loc_us-gaap_GainLossOnInvestments_5374c51d-bd4c-4c1a-9f95-164ef8fb15ef" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealizedInvestmentGainsLosses_041b9f64-f844-4e49-bf67-d415868b774b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RealizedInvestmentGainsLosses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_765e149b-d987-4f2e-bc62-f11735fdde04" xlink:to="loc_us-gaap_RealizedInvestmentGainsLosses_041b9f64-f844-4e49-bf67-d415868b774b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_976df79d-c218-4ca1-95b9-c69a71504ddf" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfEquityMethodInvestmentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_765e149b-d987-4f2e-bc62-f11735fdde04" xlink:to="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_976df79d-c218-4ca1-95b9-c69a71504ddf" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_147b2f95-1c44-423c-bf1c-0cc2ecbd179f" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_976df79d-c218-4ca1-95b9-c69a71504ddf" xlink:to="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_147b2f95-1c44-423c-bf1c-0cc2ecbd179f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_147b2f95-1c44-423c-bf1c-0cc2ecbd179f_default" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_147b2f95-1c44-423c-bf1c-0cc2ecbd179f" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_147b2f95-1c44-423c-bf1c-0cc2ecbd179f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_d73f413a-b63b-4035-bf1b-377ed22c7042" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_147b2f95-1c44-423c-bf1c-0cc2ecbd179f" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_d73f413a-b63b-4035-bf1b-377ed22c7042" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_CrowdStrikeHoldingsIncMember_d67950b2-d651-4f41-b957-cebdd87ba094" xlink:href="rxt-20201231.xsd#rxt_CrowdStrikeHoldingsIncMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_d73f413a-b63b-4035-bf1b-377ed22c7042" xlink:to="loc_rxt_CrowdStrikeHoldingsIncMember_d67950b2-d651-4f41-b957-cebdd87ba094" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_MailgunTechnologiesMember_4539e263-e1df-4676-8c4d-41e7045efce3" xlink:href="rxt-20201231.xsd#rxt_MailgunTechnologiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_d73f413a-b63b-4035-bf1b-377ed22c7042" xlink:to="loc_rxt_MailgunTechnologiesMember_4539e263-e1df-4676-8c4d-41e7045efce3" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.rackspace.com/role/Debt" xlink:type="simple" xlink:href="rxt-20201231.xsd#Debt"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/Debt" xlink:type="extended" id="i414b780d96a1435cb8185d3cf9b03b7c_Debt"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/DebtTables" xlink:type="simple" xlink:href="rxt-20201231.xsd#DebtTables"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/DebtTables" xlink:type="extended" id="i534592c4af9a41b0839646c030edc480_DebtTables"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/DebtScheduleofDebtDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#DebtScheduleofDebtDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/DebtScheduleofDebtDetails" xlink:type="extended" id="ied44d88e98114551a6d3256d41e4887d_DebtScheduleofDebtDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_137544a1-40f5-41d7-823f-861083f62591" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_abc6e2fd-3e3e-4f06-ace2-bdf36c356401" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_137544a1-40f5-41d7-823f-861083f62591" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_abc6e2fd-3e3e-4f06-ace2-bdf36c356401" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredFinanceCostsNet_9914264f-b88e-4e92-b76e-d27a2e2c4f9d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredFinanceCostsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_137544a1-40f5-41d7-823f-861083f62591" xlink:to="loc_us-gaap_DeferredFinanceCostsNet_9914264f-b88e-4e92-b76e-d27a2e2c4f9d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentUnamortizedDiscount_1754dc18-0c07-4db3-9747-f51a511b3d19" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentUnamortizedDiscount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_137544a1-40f5-41d7-823f-861083f62591" xlink:to="loc_us-gaap_DebtInstrumentUnamortizedDiscount_1754dc18-0c07-4db3-9747-f51a511b3d19" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_f85074e4-4904-4068-9ccc-a224bd9a083a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_137544a1-40f5-41d7-823f-861083f62591" xlink:to="loc_us-gaap_LongTermDebt_f85074e4-4904-4068-9ccc-a224bd9a083a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtCurrent_5adad4d1-d4de-410f-ad25-bce5a6406798" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongTermDebtCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_137544a1-40f5-41d7-823f-861083f62591" xlink:to="loc_us-gaap_LongTermDebtCurrent_5adad4d1-d4de-410f-ad25-bce5a6406798" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtNoncurrent_729de989-329e-4a57-85a5-f029b86a778c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongTermDebtNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_137544a1-40f5-41d7-823f-861083f62591" xlink:to="loc_us-gaap_LongTermDebtNoncurrent_729de989-329e-4a57-85a5-f029b86a778c" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_ba6dd41d-57a6-40c3-9c3b-6a5b58286c93" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_137544a1-40f5-41d7-823f-861083f62591" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_ba6dd41d-57a6-40c3-9c3b-6a5b58286c93" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_3cfb3843-8c3c-4f56-ae19-3747abd9c41e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_137544a1-40f5-41d7-823f-861083f62591" xlink:to="loc_us-gaap_DebtInstrumentTable_3cfb3843-8c3c-4f56-ae19-3747abd9c41e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_572ce52e-b3be-42ca-b661-1298d2db373b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_3cfb3843-8c3c-4f56-ae19-3747abd9c41e" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_572ce52e-b3be-42ca-b661-1298d2db373b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_572ce52e-b3be-42ca-b661-1298d2db373b_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_572ce52e-b3be-42ca-b661-1298d2db373b" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_572ce52e-b3be-42ca-b661-1298d2db373b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_54c6073a-2e8e-4458-9bc8-e4718a15ed5e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_572ce52e-b3be-42ca-b661-1298d2db373b" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_54c6073a-2e8e-4458-9bc8-e4718a15ed5e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebtMember_b2af94a5-8a76-407f-9475-ab040e649a6c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_54c6073a-2e8e-4458-9bc8-e4718a15ed5e" xlink:to="loc_us-gaap_SecuredDebtMember_b2af94a5-8a76-407f-9475-ab040e649a6c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorNotesMember_97694fe2-5ee3-4e54-99e5-dffd3e1c2e62" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_54c6073a-2e8e-4458-9bc8-e4718a15ed5e" xlink:to="loc_us-gaap_SeniorNotesMember_97694fe2-5ee3-4e54-99e5-dffd3e1c2e62" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_d492cc38-955d-4b6a-9dca-9ae8a9ab92b5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_54c6073a-2e8e-4458-9bc8-e4718a15ed5e" xlink:to="loc_us-gaap_LineOfCreditMember_d492cc38-955d-4b6a-9dca-9ae8a9ab92b5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_ba7b789a-41c1-4093-bac0-384c49cd67b6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_3cfb3843-8c3c-4f56-ae19-3747abd9c41e" xlink:to="loc_us-gaap_DebtInstrumentAxis_ba7b789a-41c1-4093-bac0-384c49cd67b6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_ba7b789a-41c1-4093-bac0-384c49cd67b6_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_ba7b789a-41c1-4093-bac0-384c49cd67b6" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_ba7b789a-41c1-4093-bac0-384c49cd67b6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_08abac1c-ce51-4420-8bbd-c029de344daf" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_ba7b789a-41c1-4093-bac0-384c49cd67b6" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_08abac1c-ce51-4420-8bbd-c029de344daf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_A8625SeniorNotesDue2024Member_e1e9ada3-a6a6-485e-91e6-8d267e20dcd9" xlink:href="rxt-20201231.xsd#rxt_A8625SeniorNotesDue2024Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_08abac1c-ce51-4420-8bbd-c029de344daf" xlink:to="loc_rxt_A8625SeniorNotesDue2024Member_e1e9ada3-a6a6-485e-91e6-8d267e20dcd9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_ReceivablesFinancingFacilityMember_a625e857-127a-4967-a82a-572582fc8151" xlink:href="rxt-20201231.xsd#rxt_ReceivablesFinancingFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_08abac1c-ce51-4420-8bbd-c029de344daf" xlink:to="loc_rxt_ReceivablesFinancingFacilityMember_a625e857-127a-4967-a82a-572582fc8151" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_FirstLienCreditAgreementMember_11b10ddc-0edb-4f80-8cd3-e607b24aca5a" xlink:href="rxt-20201231.xsd#rxt_FirstLienCreditAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_08abac1c-ce51-4420-8bbd-c029de344daf" xlink:to="loc_rxt_FirstLienCreditAgreementMember_11b10ddc-0edb-4f80-8cd3-e607b24aca5a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_SeniorNotes5375Due2028Member_55f8e84a-2135-4478-b8d5-cef739f799d0" xlink:href="rxt-20201231.xsd#rxt_SeniorNotes5375Due2028Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_08abac1c-ce51-4420-8bbd-c029de344daf" xlink:to="loc_rxt_SeniorNotes5375Due2028Member_55f8e84a-2135-4478-b8d5-cef739f799d0" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.rackspace.com/role/DebtNarrativeDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#DebtNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/DebtNarrativeDetails" xlink:type="extended" id="ib4e1416ff716438db49fe09d23b9d69c_DebtNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_c9e31b5d-ee71-4856-9ba5-e517809048e3" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_ff42ebd4-00b8-47fc-b4f4-38b27826ab2a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c9e31b5d-ee71-4856-9ba5-e517809048e3" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_ff42ebd4-00b8-47fc-b4f4-38b27826ab2a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_b5655e2b-1fbe-4294-9aff-74d54c04440a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c9e31b5d-ee71-4856-9ba5-e517809048e3" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_b5655e2b-1fbe-4294-9aff-74d54c04440a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_DebtInstrumentBasisSpreadOnVariableRateFloor_354fb934-8adc-4a13-8a41-67814fd74bfe" xlink:href="rxt-20201231.xsd#rxt_DebtInstrumentBasisSpreadOnVariableRateFloor"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c9e31b5d-ee71-4856-9ba5-e517809048e3" xlink:to="loc_rxt_DebtInstrumentBasisSpreadOnVariableRateFloor_354fb934-8adc-4a13-8a41-67814fd74bfe" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_bb65db5f-fbe7-423f-b1b0-966850b191f9" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c9e31b5d-ee71-4856-9ba5-e517809048e3" xlink:to="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_bb65db5f-fbe7-423f-b1b0-966850b191f9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_DebtInstrumentInterestPaymentPeriod_c0a0be1e-73db-4a61-8da9-9dec4daf3e93" xlink:href="rxt-20201231.xsd#rxt_DebtInstrumentInterestPaymentPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c9e31b5d-ee71-4856-9ba5-e517809048e3" xlink:to="loc_rxt_DebtInstrumentInterestPaymentPeriod_c0a0be1e-73db-4a61-8da9-9dec4daf3e93" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_DebtInstrumentPeriodicPaymentPercentageOfOriginalPrincipalAmount_92f2dc04-ee8d-49ce-99ca-2f44473ffaa3" xlink:href="rxt-20201231.xsd#rxt_DebtInstrumentPeriodicPaymentPercentageOfOriginalPrincipalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c9e31b5d-ee71-4856-9ba5-e517809048e3" xlink:to="loc_rxt_DebtInstrumentPeriodicPaymentPercentageOfOriginalPrincipalAmount_92f2dc04-ee8d-49ce-99ca-2f44473ffaa3" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentPeriodicPaymentPrincipal_197d9a3c-d8a0-4316-b90b-f3049c253871" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentPeriodicPaymentPrincipal"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c9e31b5d-ee71-4856-9ba5-e517809048e3" xlink:to="loc_us-gaap_DebtInstrumentPeriodicPaymentPrincipal_197d9a3c-d8a0-4316-b90b-f3049c253871" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_DebtInstrumentCovenantLeverageRatioMaximum_bd0a2f8b-a2d2-4220-8514-8bc4414765b1" xlink:href="rxt-20201231.xsd#rxt_DebtInstrumentCovenantLeverageRatioMaximum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c9e31b5d-ee71-4856-9ba5-e517809048e3" xlink:to="loc_rxt_DebtInstrumentCovenantLeverageRatioMaximum_bd0a2f8b-a2d2-4220-8514-8bc4414765b1" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_DebtInstrumentCovenantUndrawnLettersOfCreditAndCashCollateralizedLettersOfCreditExcludedFromThresholdTrigger_521b4bb3-d4cc-429e-9910-746801e27a92" xlink:href="rxt-20201231.xsd#rxt_DebtInstrumentCovenantUndrawnLettersOfCreditAndCashCollateralizedLettersOfCreditExcludedFromThresholdTrigger"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c9e31b5d-ee71-4856-9ba5-e517809048e3" xlink:to="loc_rxt_DebtInstrumentCovenantUndrawnLettersOfCreditAndCashCollateralizedLettersOfCreditExcludedFromThresholdTrigger_521b4bb3-d4cc-429e-9910-746801e27a92" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_DebtInstrumentCovenantPercentageOfOutstandingBorrowingsTriggerMinimum_bb765f04-6f4b-46b1-9d2b-91656edbfd84" xlink:href="rxt-20201231.xsd#rxt_DebtInstrumentCovenantPercentageOfOutstandingBorrowingsTriggerMinimum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c9e31b5d-ee71-4856-9ba5-e517809048e3" xlink:to="loc_rxt_DebtInstrumentCovenantPercentageOfOutstandingBorrowingsTriggerMinimum_bb765f04-6f4b-46b1-9d2b-91656edbfd84" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtIssuanceCostsLineOfCreditArrangementsNet_dda1d149-6427-45b7-b81a-b0e878e962c2" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtIssuanceCostsLineOfCreditArrangementsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c9e31b5d-ee71-4856-9ba5-e517809048e3" xlink:to="loc_us-gaap_DebtIssuanceCostsLineOfCreditArrangementsNet_dda1d149-6427-45b7-b81a-b0e878e962c2" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtTerm_05bae8c6-6385-4b9d-99d2-4bd6bffe1a7b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongTermDebtTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c9e31b5d-ee71-4856-9ba5-e517809048e3" xlink:to="loc_us-gaap_LongTermDebtTerm_05bae8c6-6385-4b9d-99d2-4bd6bffe1a7b" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromLongTermLinesOfCredit_627d906d-46ab-4cc2-b774-1855f164db26" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProceedsFromLongTermLinesOfCredit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c9e31b5d-ee71-4856-9ba5-e517809048e3" xlink:to="loc_us-gaap_ProceedsFromLongTermLinesOfCredit_627d906d-46ab-4cc2-b774-1855f164db26" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfLongTermLinesOfCredit_6b261e42-c370-45b8-8453-5e6286d3f2ed" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RepaymentsOfLongTermLinesOfCredit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c9e31b5d-ee71-4856-9ba5-e517809048e3" xlink:to="loc_us-gaap_RepaymentsOfLongTermLinesOfCredit_6b261e42-c370-45b8-8453-5e6286d3f2ed" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_38f973bc-c0f5-4b56-8422-c06d9193ee35" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c9e31b5d-ee71-4856-9ba5-e517809048e3" xlink:to="loc_us-gaap_LongTermDebt_38f973bc-c0f5-4b56-8422-c06d9193ee35" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateEffectivePercentage_ea00d48a-0af4-4a24-9eb0-4accdbcef302" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentInterestRateEffectivePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c9e31b5d-ee71-4856-9ba5-e517809048e3" xlink:to="loc_us-gaap_DebtInstrumentInterestRateEffectivePercentage_ea00d48a-0af4-4a24-9eb0-4accdbcef302" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtFairValue_ee337ca2-ea4e-4faf-a4cb-9bbed98a78e1" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongTermDebtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c9e31b5d-ee71-4856-9ba5-e517809048e3" xlink:to="loc_us-gaap_LongTermDebtFairValue_ee337ca2-ea4e-4faf-a4cb-9bbed98a78e1" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_8a074853-7f3e-440a-89e2-dbfc121bd587" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c9e31b5d-ee71-4856-9ba5-e517809048e3" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_8a074853-7f3e-440a-89e2-dbfc121bd587" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_35eb5da5-d62c-4bf5-9afb-4c1e8150d05d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c9e31b5d-ee71-4856-9ba5-e517809048e3" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_35eb5da5-d62c-4bf5-9afb-4c1e8150d05d" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredFinanceCostsGross_9e0d01e7-a756-4777-aa3f-ab71ca8cbf22" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredFinanceCostsGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c9e31b5d-ee71-4856-9ba5-e517809048e3" xlink:to="loc_us-gaap_DeferredFinanceCostsGross_9e0d01e7-a756-4777-aa3f-ab71ca8cbf22" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ExtinguishmentOfDebtAmount_86aa4ef0-85f2-421f-951c-90cdf8e47d49" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ExtinguishmentOfDebtAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c9e31b5d-ee71-4856-9ba5-e517809048e3" xlink:to="loc_us-gaap_ExtinguishmentOfDebtAmount_86aa4ef0-85f2-421f-951c-90cdf8e47d49" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarlyRepaymentOfSeniorDebt_0ccd4397-de37-4246-9338-413d1c3106f4" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EarlyRepaymentOfSeniorDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c9e31b5d-ee71-4856-9ba5-e517809048e3" xlink:to="loc_us-gaap_EarlyRepaymentOfSeniorDebt_0ccd4397-de37-4246-9338-413d1c3106f4" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_ExtinguishmentOfDebtInterestPayableAmount_6e71f2f4-ff99-4b32-b728-990de3cc1254" xlink:href="rxt-20201231.xsd#rxt_ExtinguishmentOfDebtInterestPayableAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c9e31b5d-ee71-4856-9ba5-e517809048e3" xlink:to="loc_rxt_ExtinguishmentOfDebtInterestPayableAmount_6e71f2f4-ff99-4b32-b728-990de3cc1254" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRepurchasedFaceAmount_fb595957-02cc-44fa-84ac-745aa44e0ce7" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentRepurchasedFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c9e31b5d-ee71-4856-9ba5-e517809048e3" xlink:to="loc_us-gaap_DebtInstrumentRepurchasedFaceAmount_fb595957-02cc-44fa-84ac-745aa44e0ce7" xlink:type="arc" order="23"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_85b342c8-614e-469f-81eb-c223ec2bf952" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GainsLossesOnExtinguishmentOfDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c9e31b5d-ee71-4856-9ba5-e517809048e3" xlink:to="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_85b342c8-614e-469f-81eb-c223ec2bf952" xlink:type="arc" order="24"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_PremiumOnRepurchaseExtinguishmentOfDebt_4def9b2d-4091-4517-8554-8341965f6421" xlink:href="rxt-20201231.xsd#rxt_PremiumOnRepurchaseExtinguishmentOfDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c9e31b5d-ee71-4856-9ba5-e517809048e3" xlink:to="loc_rxt_PremiumOnRepurchaseExtinguishmentOfDebt_4def9b2d-4091-4517-8554-8341965f6421" xlink:type="arc" order="25"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WriteOffOfDeferredDebtIssuanceCost_ce8281a6-cf9b-476e-8b69-1ca9bfbaa6db" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_WriteOffOfDeferredDebtIssuanceCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c9e31b5d-ee71-4856-9ba5-e517809048e3" xlink:to="loc_us-gaap_WriteOffOfDeferredDebtIssuanceCost_ce8281a6-cf9b-476e-8b69-1ca9bfbaa6db" xlink:type="arc" order="26"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfDebtExtinguishmentCosts_8a248628-dc56-45c7-94e4-584073cdb3c5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsOfDebtExtinguishmentCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c9e31b5d-ee71-4856-9ba5-e517809048e3" xlink:to="loc_us-gaap_PaymentsOfDebtExtinguishmentCosts_8a248628-dc56-45c7-94e4-584073cdb3c5" xlink:type="arc" order="27"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPricePercentage_d33e8b8a-c019-43ab-b982-8cb06d003204" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentRedemptionPricePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c9e31b5d-ee71-4856-9ba5-e517809048e3" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPricePercentage_d33e8b8a-c019-43ab-b982-8cb06d003204" xlink:type="arc" order="28"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_DebtInstrumentPrincipalAmountOutstandingSubjectToRedemptionPercentage_921a9e23-d9fb-4a06-a836-b4ec67b87dee" xlink:href="rxt-20201231.xsd#rxt_DebtInstrumentPrincipalAmountOutstandingSubjectToRedemptionPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c9e31b5d-ee71-4856-9ba5-e517809048e3" xlink:to="loc_rxt_DebtInstrumentPrincipalAmountOutstandingSubjectToRedemptionPercentage_921a9e23-d9fb-4a06-a836-b4ec67b87dee" xlink:type="arc" order="29"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFairValue_94377232-e07c-4df3-a938-f508547f102a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c9e31b5d-ee71-4856-9ba5-e517809048e3" xlink:to="loc_us-gaap_DebtInstrumentFairValue_94377232-e07c-4df3-a938-f508547f102a" xlink:type="arc" order="30"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfDebt_0cfef37f-7676-458a-8e93-b9ebf96d6efa" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RepaymentsOfDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c9e31b5d-ee71-4856-9ba5-e517809048e3" xlink:to="loc_us-gaap_RepaymentsOfDebt_0cfef37f-7676-458a-8e93-b9ebf96d6efa" xlink:type="arc" order="31"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd_7f9d4da1-3783-4350-8b9a-8c1c9b2babce" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c9e31b5d-ee71-4856-9ba5-e517809048e3" xlink:to="loc_us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd_7f9d4da1-3783-4350-8b9a-8c1c9b2babce" xlink:type="arc" order="32"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_f4fb0f3d-fdb2-4dcb-b76c-a73bebe0374f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c9e31b5d-ee71-4856-9ba5-e517809048e3" xlink:to="loc_us-gaap_DebtInstrumentTable_f4fb0f3d-fdb2-4dcb-b76c-a73bebe0374f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_74234545-3ad8-418f-95a7-c9f49a3b0e48" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_f4fb0f3d-fdb2-4dcb-b76c-a73bebe0374f" xlink:to="loc_us-gaap_CreditFacilityAxis_74234545-3ad8-418f-95a7-c9f49a3b0e48" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_74234545-3ad8-418f-95a7-c9f49a3b0e48_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_74234545-3ad8-418f-95a7-c9f49a3b0e48" xlink:to="loc_us-gaap_CreditFacilityDomain_74234545-3ad8-418f-95a7-c9f49a3b0e48_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_f50395c1-60b2-4e28-9fbf-25ef4127235c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_74234545-3ad8-418f-95a7-c9f49a3b0e48" xlink:to="loc_us-gaap_CreditFacilityDomain_f50395c1-60b2-4e28-9fbf-25ef4127235c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_6230140a-eb42-41e4-a166-919a92391e79" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_f50395c1-60b2-4e28-9fbf-25ef4127235c" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_6230140a-eb42-41e4-a166-919a92391e79" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_c587d013-5133-45b8-903f-e9995a109b66" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_f4fb0f3d-fdb2-4dcb-b76c-a73bebe0374f" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_c587d013-5133-45b8-903f-e9995a109b66" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_c587d013-5133-45b8-903f-e9995a109b66_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_c587d013-5133-45b8-903f-e9995a109b66" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_c587d013-5133-45b8-903f-e9995a109b66_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_e558dda1-5d3c-49d5-bf03-4f5376ed74ae" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_c587d013-5133-45b8-903f-e9995a109b66" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_e558dda1-5d3c-49d5-bf03-4f5376ed74ae" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_cbfda9b9-9128-41b4-99c8-d81648e8aa4f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_e558dda1-5d3c-49d5-bf03-4f5376ed74ae" xlink:to="loc_us-gaap_LineOfCreditMember_cbfda9b9-9128-41b4-99c8-d81648e8aa4f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebtMember_c22f9b99-5ac1-4c48-9b9e-0d009de8a17f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_e558dda1-5d3c-49d5-bf03-4f5376ed74ae" xlink:to="loc_us-gaap_SecuredDebtMember_c22f9b99-5ac1-4c48-9b9e-0d009de8a17f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorNotesMember_d6bfa0c2-d75d-4563-8bd6-160ae5f67819" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_e558dda1-5d3c-49d5-bf03-4f5376ed74ae" xlink:to="loc_us-gaap_SeniorNotesMember_d6bfa0c2-d75d-4563-8bd6-160ae5f67819" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_3d47d2df-78d4-4cdc-9562-cffb90ad3ca4" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_f4fb0f3d-fdb2-4dcb-b76c-a73bebe0374f" xlink:to="loc_us-gaap_DebtInstrumentAxis_3d47d2df-78d4-4cdc-9562-cffb90ad3ca4" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_3d47d2df-78d4-4cdc-9562-cffb90ad3ca4_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_3d47d2df-78d4-4cdc-9562-cffb90ad3ca4" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_3d47d2df-78d4-4cdc-9562-cffb90ad3ca4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_95bcd87a-cb2f-4444-9382-fd7d72c8b1ef" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_3d47d2df-78d4-4cdc-9562-cffb90ad3ca4" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_95bcd87a-cb2f-4444-9382-fd7d72c8b1ef" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_FirstLienCreditAgreementMember_c73b1e6a-0b27-4e66-bdee-b861022a7aef" xlink:href="rxt-20201231.xsd#rxt_FirstLienCreditAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_95bcd87a-cb2f-4444-9382-fd7d72c8b1ef" xlink:to="loc_rxt_FirstLienCreditAgreementMember_c73b1e6a-0b27-4e66-bdee-b861022a7aef" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_A8625SeniorNotesDue2024Member_dd3cd3b9-ce86-4162-b815-6520ff89e218" xlink:href="rxt-20201231.xsd#rxt_A8625SeniorNotesDue2024Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_95bcd87a-cb2f-4444-9382-fd7d72c8b1ef" xlink:to="loc_rxt_A8625SeniorNotesDue2024Member_dd3cd3b9-ce86-4162-b815-6520ff89e218" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_ReceivablesFinancingFacilityMember_7f568962-4c30-4f3f-9269-578a56dc052a" xlink:href="rxt-20201231.xsd#rxt_ReceivablesFinancingFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_95bcd87a-cb2f-4444-9382-fd7d72c8b1ef" xlink:to="loc_rxt_ReceivablesFinancingFacilityMember_7f568962-4c30-4f3f-9269-578a56dc052a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_SeniorNotes5375Due2028Member_bf1774ea-a1ff-4c5d-a2d3-f4b57aa92dda" xlink:href="rxt-20201231.xsd#rxt_SeniorNotes5375Due2028Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_95bcd87a-cb2f-4444-9382-fd7d72c8b1ef" xlink:to="loc_rxt_SeniorNotes5375Due2028Member_bf1774ea-a1ff-4c5d-a2d3-f4b57aa92dda" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateAxis_36c39dc5-7b8d-41a7-9a44-cb2949f5b58f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_VariableRateAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_f4fb0f3d-fdb2-4dcb-b76c-a73bebe0374f" xlink:to="loc_us-gaap_VariableRateAxis_36c39dc5-7b8d-41a7-9a44-cb2949f5b58f" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_36c39dc5-7b8d-41a7-9a44-cb2949f5b58f_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VariableRateAxis_36c39dc5-7b8d-41a7-9a44-cb2949f5b58f" xlink:to="loc_us-gaap_VariableRateDomain_36c39dc5-7b8d-41a7-9a44-cb2949f5b58f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_27fcb66f-db13-4a46-b70e-0c4359f6e20c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VariableRateAxis_36c39dc5-7b8d-41a7-9a44-cb2949f5b58f" xlink:to="loc_us-gaap_VariableRateDomain_27fcb66f-db13-4a46-b70e-0c4359f6e20c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LondonInterbankOfferedRateLIBORMember_9daa37e2-3495-4a6c-ac12-0fa3e836a5fc" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LondonInterbankOfferedRateLIBORMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_27fcb66f-db13-4a46-b70e-0c4359f6e20c" xlink:to="loc_us-gaap_LondonInterbankOfferedRateLIBORMember_9daa37e2-3495-4a6c-ac12-0fa3e836a5fc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BaseRateMember_40c0bcf6-024a-4ac0-a4e1-81f149257891" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BaseRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_27fcb66f-db13-4a46-b70e-0c4359f6e20c" xlink:to="loc_us-gaap_BaseRateMember_40c0bcf6-024a-4ac0-a4e1-81f149257891" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationAxis_116c3c0f-5b86-4dd8-8c73-b24727a3f81b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BalanceSheetLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_f4fb0f3d-fdb2-4dcb-b76c-a73bebe0374f" xlink:to="loc_us-gaap_BalanceSheetLocationAxis_116c3c0f-5b86-4dd8-8c73-b24727a3f81b" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_116c3c0f-5b86-4dd8-8c73-b24727a3f81b_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BalanceSheetLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_116c3c0f-5b86-4dd8-8c73-b24727a3f81b" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_116c3c0f-5b86-4dd8-8c73-b24727a3f81b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_80719ea1-71f0-479c-8836-d45a0cbc26e0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BalanceSheetLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_116c3c0f-5b86-4dd8-8c73-b24727a3f81b" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_80719ea1-71f0-479c-8836-d45a0cbc26e0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNoncurrentAssetsMember_09e93587-7dd3-4ba3-ba79-c86b0be45c03" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherNoncurrentAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_80719ea1-71f0-479c-8836-d45a0cbc26e0" xlink:to="loc_us-gaap_OtherNoncurrentAssetsMember_09e93587-7dd3-4ba3-ba79-c86b0be45c03" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_15229f41-a296-4470-a694-d591e4badcc1" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_f4fb0f3d-fdb2-4dcb-b76c-a73bebe0374f" xlink:to="loc_srt_RangeAxis_15229f41-a296-4470-a694-d591e4badcc1" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_15229f41-a296-4470-a694-d591e4badcc1_default" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_15229f41-a296-4470-a694-d591e4badcc1" xlink:to="loc_srt_RangeMember_15229f41-a296-4470-a694-d591e4badcc1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_63e59603-552b-425d-a0e8-3904c85fedc2" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_15229f41-a296-4470-a694-d591e4badcc1" xlink:to="loc_srt_RangeMember_63e59603-552b-425d-a0e8-3904c85fedc2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_a86a4193-cf35-4569-8293-ff04aff58ffc" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_63e59603-552b-425d-a0e8-3904c85fedc2" xlink:to="loc_srt_MaximumMember_a86a4193-cf35-4569-8293-ff04aff58ffc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPeriodAxis_ee7fc27d-4e56-45e2-9bff-95ca98b5cd6a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentRedemptionPeriodAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_f4fb0f3d-fdb2-4dcb-b76c-a73bebe0374f" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPeriodAxis_ee7fc27d-4e56-45e2-9bff-95ca98b5cd6a" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPeriodDomain_ee7fc27d-4e56-45e2-9bff-95ca98b5cd6a_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentRedemptionPeriodDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentRedemptionPeriodAxis_ee7fc27d-4e56-45e2-9bff-95ca98b5cd6a" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPeriodDomain_ee7fc27d-4e56-45e2-9bff-95ca98b5cd6a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPeriodDomain_7b7e3fbb-60ac-4e60-bcfd-5aeff97e09c0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentRedemptionPeriodDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentRedemptionPeriodAxis_ee7fc27d-4e56-45e2-9bff-95ca98b5cd6a" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPeriodDomain_7b7e3fbb-60ac-4e60-bcfd-5aeff97e09c0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPeriodOneMember_7eca4403-ba9d-418c-b29c-c7e73f9c5462" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentRedemptionPeriodOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentRedemptionPeriodDomain_7b7e3fbb-60ac-4e60-bcfd-5aeff97e09c0" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPeriodOneMember_7eca4403-ba9d-418c-b29c-c7e73f9c5462" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPeriodTwoMember_88632428-c604-4f22-9eb7-25f1bf44b075" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentRedemptionPeriodTwoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentRedemptionPeriodDomain_7b7e3fbb-60ac-4e60-bcfd-5aeff97e09c0" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPeriodTwoMember_88632428-c604-4f22-9eb7-25f1bf44b075" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPeriodThreeMember_1b690c41-e797-4870-83c4-70fd9d36db04" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentRedemptionPeriodThreeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentRedemptionPeriodDomain_7b7e3fbb-60ac-4e60-bcfd-5aeff97e09c0" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPeriodThreeMember_1b690c41-e797-4870-83c4-70fd9d36db04" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPeriodFourMember_ef445924-8e86-4c19-9604-5a2b8b361b47" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentRedemptionPeriodFourMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentRedemptionPeriodDomain_7b7e3fbb-60ac-4e60-bcfd-5aeff97e09c0" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPeriodFourMember_ef445924-8e86-4c19-9604-5a2b8b361b47" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_f2ea17ef-cd50-4e13-bac9-98ac2f581940" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_f4fb0f3d-fdb2-4dcb-b76c-a73bebe0374f" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_f2ea17ef-cd50-4e13-bac9-98ac2f581940" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_f2ea17ef-cd50-4e13-bac9-98ac2f581940_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_f2ea17ef-cd50-4e13-bac9-98ac2f581940" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_f2ea17ef-cd50-4e13-bac9-98ac2f581940_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_fb646590-0c85-4d2d-85e1-fbf8a8f37a13" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_f2ea17ef-cd50-4e13-bac9-98ac2f581940" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_fb646590-0c85-4d2d-85e1-fbf8a8f37a13" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_0f247a6e-2497-458c-8cea-aa3b95e84a23" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_fb646590-0c85-4d2d-85e1-fbf8a8f37a13" xlink:to="loc_us-gaap_SubsequentEventMember_0f247a6e-2497-458c-8cea-aa3b95e84a23" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.rackspace.com/role/DebtMaturitiesDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#DebtMaturitiesDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/DebtMaturitiesDetails" xlink:type="extended" id="ib39dcc9beb7f4c429ee2f67021890b62_DebtMaturitiesDetails"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/Leases" xlink:type="simple" xlink:href="rxt-20201231.xsd#Leases"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/Leases" xlink:type="extended" id="iffc8c45aac114b27a169abec1f739103_Leases"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/LeasesTables" xlink:type="simple" xlink:href="rxt-20201231.xsd#LeasesTables"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/LeasesTables" xlink:type="extended" id="ic8c4e657b351412e881acec60b61a7a5_LeasesTables"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/LeasesPropertyandEquipmentUnderFinanceLeasesDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#LeasesPropertyandEquipmentUnderFinanceLeasesDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/LeasesPropertyandEquipmentUnderFinanceLeasesDetails" xlink:type="extended" id="i60dd39ef64664dc89934a9be0d06d1e2_LeasesPropertyandEquipmentUnderFinanceLeasesDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeLeaseDescriptionLineItems_3aeabb01-0eb6-4913-8b62-ef2a04c0a419" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LesseeLeaseDescriptionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseRightOfUseAssetBeforeAccumulatedAmortization_703010b1-5e6e-413d-8304-db452c00588d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FinanceLeaseRightOfUseAssetBeforeAccumulatedAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_3aeabb01-0eb6-4913-8b62-ef2a04c0a419" xlink:to="loc_us-gaap_FinanceLeaseRightOfUseAssetBeforeAccumulatedAmortization_703010b1-5e6e-413d-8304-db452c00588d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseRightOfUseAssetAccumulatedAmortization_504fa742-3c0f-46de-89b6-df26bb59236d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FinanceLeaseRightOfUseAssetAccumulatedAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_3aeabb01-0eb6-4913-8b62-ef2a04c0a419" xlink:to="loc_us-gaap_FinanceLeaseRightOfUseAssetAccumulatedAmortization_504fa742-3c0f-46de-89b6-df26bb59236d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseRightOfUseAsset_3be656ba-4d35-43da-9bd8-31f3e1da7f72" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FinanceLeaseRightOfUseAsset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_3aeabb01-0eb6-4913-8b62-ef2a04c0a419" xlink:to="loc_us-gaap_FinanceLeaseRightOfUseAsset_3be656ba-4d35-43da-9bd8-31f3e1da7f72" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_NonCashIncreaseInBuildingsWithinPropertyEquipmentNetAndSoftwareDueToLeaseModification_2fd52a19-b168-4bea-8d51-5538cd2bc590" xlink:href="rxt-20201231.xsd#rxt_NonCashIncreaseInBuildingsWithinPropertyEquipmentNetAndSoftwareDueToLeaseModification"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_3aeabb01-0eb6-4913-8b62-ef2a04c0a419" xlink:to="loc_rxt_NonCashIncreaseInBuildingsWithinPropertyEquipmentNetAndSoftwareDueToLeaseModification_2fd52a19-b168-4bea-8d51-5538cd2bc590" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeLeaseDescriptionTable_71dac900-0fe4-4ecf-9c8e-afc4af60e1d0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LesseeLeaseDescriptionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_3aeabb01-0eb6-4913-8b62-ef2a04c0a419" xlink:to="loc_us-gaap_LesseeLeaseDescriptionTable_71dac900-0fe4-4ecf-9c8e-afc4af60e1d0" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_620d01a8-9e4f-4496-84e9-f46669ee1d33" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LesseeLeaseDescriptionTable_71dac900-0fe4-4ecf-9c8e-afc4af60e1d0" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_620d01a8-9e4f-4496-84e9-f46669ee1d33" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_620d01a8-9e4f-4496-84e9-f46669ee1d33_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_620d01a8-9e4f-4496-84e9-f46669ee1d33" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_620d01a8-9e4f-4496-84e9-f46669ee1d33_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_12f0d88b-75a7-42e9-94fd-38c543073e13" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_620d01a8-9e4f-4496-84e9-f46669ee1d33" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_12f0d88b-75a7-42e9-94fd-38c543073e13" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_ComputerAndEquipmentMember_23c2e2da-7a9f-4790-a708-7c1115ed7200" xlink:href="rxt-20201231.xsd#rxt_ComputerAndEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_12f0d88b-75a7-42e9-94fd-38c543073e13" xlink:to="loc_rxt_ComputerAndEquipmentMember_23c2e2da-7a9f-4790-a708-7c1115ed7200" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BuildingMember_3a7d4494-acce-4d58-811c-a61a295f2893" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BuildingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_12f0d88b-75a7-42e9-94fd-38c543073e13" xlink:to="loc_us-gaap_BuildingMember_3a7d4494-acce-4d58-811c-a61a295f2893" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.rackspace.com/role/LeasesFinanceLeasesDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#LeasesFinanceLeasesDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/LeasesFinanceLeasesDetails" xlink:type="extended" id="i48e2564ce1c94953b1c4308384c632ae_LeasesFinanceLeasesDetails"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/LeasesCostDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#LeasesCostDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/LeasesCostDetails" xlink:type="extended" id="id29b78bda56a4411b0426cec78b6aa60_LeasesCostDetails"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/LeasesCashFlowDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#LeasesCashFlowDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/LeasesCashFlowDetails" xlink:type="extended" id="i5d1b138aedf640fab2ed7dccb066c0c3_LeasesCashFlowDetails"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/LeasesSupplementalInformationDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#LeasesSupplementalInformationDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/LeasesSupplementalInformationDetails" xlink:type="extended" id="i8c743573c7c0479f9084c837387c06b7_LeasesSupplementalInformationDetails"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/LeasesMaturityDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#LeasesMaturityDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/LeasesMaturityDetails" xlink:type="extended" id="i74c24db59f16499f8cad5e0b7ecdf730_LeasesMaturityDetails"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/FinancingObligations" xlink:type="simple" xlink:href="rxt-20201231.xsd#FinancingObligations"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/FinancingObligations" xlink:type="extended" id="i17194f75a63b4f4b90f1ada798d2d4df_FinancingObligations"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/FinancingObligationsTables" xlink:type="simple" xlink:href="rxt-20201231.xsd#FinancingObligationsTables"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/FinancingObligationsTables" xlink:type="extended" id="ied862ab58e01494694a8ad393466b994_FinancingObligationsTables"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/FinancingObligationsNarrativeDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#FinancingObligationsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/FinancingObligationsNarrativeDetails" xlink:type="extended" id="i4fb51e33c3a445d7b34aeacef9aa1c3d_FinancingObligationsNarrativeDetails"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/FinancingObligationsFuturePaymentsUnderFinancingObligationsDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#FinancingObligationsFuturePaymentsUnderFinancingObligationsDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/FinancingObligationsFuturePaymentsUnderFinancingObligationsDetails" xlink:type="extended" id="i0c30a6a5b3f44882bcacf9aad3241c50_FinancingObligationsFuturePaymentsUnderFinancingObligationsDetails"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/CommitmentandContingencies" xlink:type="simple" xlink:href="rxt-20201231.xsd#CommitmentandContingencies"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/CommitmentandContingencies" xlink:type="extended" id="idb3ef8f3abd14557b650c743b11ba946_CommitmentandContingencies"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/CommitmentandContingenciesTables" xlink:type="simple" xlink:href="rxt-20201231.xsd#CommitmentandContingenciesTables"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/CommitmentandContingenciesTables" xlink:type="extended" id="i49f2aea335574bbc8a9517882aeee536_CommitmentandContingenciesTables"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/CommitmentandContingenciesPurchaseCommitmentsDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#CommitmentandContingenciesPurchaseCommitmentsDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/CommitmentandContingenciesPurchaseCommitmentsDetails" xlink:type="extended" id="ib0daaa9fcaf54fa8929e6be3bb0a9db2_CommitmentandContingenciesPurchaseCommitmentsDetails"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/CommitmentandContingenciesNarrativeDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#CommitmentandContingenciesNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/CommitmentandContingenciesNarrativeDetails" xlink:type="extended" id="i3259f6757cf240649e4823702be5cc17_CommitmentandContingenciesNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCommitmentsLineItems_c2b6f2b0-9b53-4404-bfa0-3a231cefb509" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherCommitmentsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GuaranteeObligationsCurrentCarryingValue_45285c4b-acec-4efb-a1af-b850ffaa5410" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GuaranteeObligationsCurrentCarryingValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_c2b6f2b0-9b53-4404-bfa0-3a231cefb509" xlink:to="loc_us-gaap_GuaranteeObligationsCurrentCarryingValue_45285c4b-acec-4efb-a1af-b850ffaa5410" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCommitmentsTable_d7d8b034-63ec-4624-969e-d50628939f29" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherCommitmentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_c2b6f2b0-9b53-4404-bfa0-3a231cefb509" xlink:to="loc_us-gaap_OtherCommitmentsTable_d7d8b034-63ec-4624-969e-d50628939f29" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GuaranteeObligationsByNatureAxis_1f971c1b-44a7-4a36-92fd-06f4ae56b9a2" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GuaranteeObligationsByNatureAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_OtherCommitmentsTable_d7d8b034-63ec-4624-969e-d50628939f29" xlink:to="loc_us-gaap_GuaranteeObligationsByNatureAxis_1f971c1b-44a7-4a36-92fd-06f4ae56b9a2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GuaranteeObligationsNatureDomain_1f971c1b-44a7-4a36-92fd-06f4ae56b9a2_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GuaranteeObligationsNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_GuaranteeObligationsByNatureAxis_1f971c1b-44a7-4a36-92fd-06f4ae56b9a2" xlink:to="loc_us-gaap_GuaranteeObligationsNatureDomain_1f971c1b-44a7-4a36-92fd-06f4ae56b9a2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GuaranteeObligationsNatureDomain_6c3c9dcc-8c54-41c2-b735-7437f7549d4f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GuaranteeObligationsNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_GuaranteeObligationsByNatureAxis_1f971c1b-44a7-4a36-92fd-06f4ae56b9a2" xlink:to="loc_us-gaap_GuaranteeObligationsNatureDomain_6c3c9dcc-8c54-41c2-b735-7437f7549d4f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndemnificationGuaranteeMember_3fb9f504-28d4-4725-8298-11d52781fe50" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IndemnificationGuaranteeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GuaranteeObligationsNatureDomain_6c3c9dcc-8c54-41c2-b735-7437f7549d4f" xlink:to="loc_us-gaap_IndemnificationGuaranteeMember_3fb9f504-28d4-4725-8298-11d52781fe50" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.rackspace.com/role/StockholdersEquity" xlink:type="simple" xlink:href="rxt-20201231.xsd#StockholdersEquity"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/StockholdersEquity" xlink:type="extended" id="i3669963bd7d74a8091c307306a423a05_StockholdersEquity"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/StockholdersEquityDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#StockholdersEquityDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/StockholdersEquityDetails" xlink:type="extended" id="i8208a95864564dccb5a954ae8572a72b_StockholdersEquityDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockLineItems_aaa88cfe-68dd-45f4-b74d-0eaeecf65882" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ClassOfStockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesIssued_8c81b128-bba3-4606-9083-2d94996a7163" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CommonStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_aaa88cfe-68dd-45f4-b74d-0eaeecf65882" xlink:to="loc_us-gaap_CommonStockSharesIssued_8c81b128-bba3-4606-9083-2d94996a7163" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_86ded7a0-a00b-4824-b23d-efb07c676820" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_aaa88cfe-68dd-45f4-b74d-0eaeecf65882" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_86ded7a0-a00b-4824-b23d-efb07c676820" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_NumberOfCommonStockClasses_10b5b0bf-3bfd-451f-aed9-8cb198496044" xlink:href="rxt-20201231.xsd#rxt_NumberOfCommonStockClasses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_aaa88cfe-68dd-45f4-b74d-0eaeecf65882" xlink:to="loc_rxt_NumberOfCommonStockClasses_10b5b0bf-3bfd-451f-aed9-8cb198496044" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_CommonStockVotesPerShare_2b9386f6-92eb-47fc-a1a2-3a248dd1c1d9" xlink:href="rxt-20201231.xsd#rxt_CommonStockVotesPerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_aaa88cfe-68dd-45f4-b74d-0eaeecf65882" xlink:to="loc_rxt_CommonStockVotesPerShare_2b9386f6-92eb-47fc-a1a2-3a248dd1c1d9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesAuthorized_9200904b-a9d8-4141-a383-038b934a2a5e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PreferredStockSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_aaa88cfe-68dd-45f4-b74d-0eaeecf65882" xlink:to="loc_us-gaap_PreferredStockSharesAuthorized_9200904b-a9d8-4141-a383-038b934a2a5e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesOutstanding_6db56743-f00e-4807-9e00-f57425b651c1" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PreferredStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_aaa88cfe-68dd-45f4-b74d-0eaeecf65882" xlink:to="loc_us-gaap_PreferredStockSharesOutstanding_6db56743-f00e-4807-9e00-f57425b651c1" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesIssued_5e52e068-cfe2-45d5-b1fd-bb7ad2aaabea" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PreferredStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_aaa88cfe-68dd-45f4-b74d-0eaeecf65882" xlink:to="loc_us-gaap_PreferredStockSharesIssued_5e52e068-cfe2-45d5-b1fd-bb7ad2aaabea" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_c71f7fd7-bfbe-4208-82d8-710f7e07489f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsForRepurchaseOfCommonStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_aaa88cfe-68dd-45f4-b74d-0eaeecf65882" xlink:to="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_c71f7fd7-bfbe-4208-82d8-710f7e07489f" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodShares_0478565d-cc9e-4487-bf5f-03f13598572a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockRepurchasedAndRetiredDuringPeriodShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_aaa88cfe-68dd-45f4-b74d-0eaeecf65882" xlink:to="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodShares_0478565d-cc9e-4487-bf5f-03f13598572a" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodValue_bf01ab65-84f1-4402-a532-f95487d25858" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockRepurchasedAndRetiredDuringPeriodValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_aaa88cfe-68dd-45f4-b74d-0eaeecf65882" xlink:to="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodValue_bf01ab65-84f1-4402-a532-f95487d25858" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued_fe29cf87-5b54-4eea-b323-05f521f7742c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_aaa88cfe-68dd-45f4-b74d-0eaeecf65882" xlink:to="loc_us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued_fe29cf87-5b54-4eea-b323-05f521f7742c" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfStockByClassTable_8f953dce-0fa4-4230-9da2-e32498993d1e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfStockByClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ClassOfStockLineItems_aaa88cfe-68dd-45f4-b74d-0eaeecf65882" xlink:to="loc_us-gaap_ScheduleOfStockByClassTable_8f953dce-0fa4-4230-9da2-e32498993d1e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_a14b58ca-6416-4282-becb-01a2ac4b080b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_8f953dce-0fa4-4230-9da2-e32498993d1e" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_a14b58ca-6416-4282-becb-01a2ac4b080b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_a14b58ca-6416-4282-becb-01a2ac4b080b_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_a14b58ca-6416-4282-becb-01a2ac4b080b" xlink:to="loc_us-gaap_EquityComponentDomain_a14b58ca-6416-4282-becb-01a2ac4b080b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_14c24c57-3034-4218-a374-41841f510d32" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_a14b58ca-6416-4282-becb-01a2ac4b080b" xlink:to="loc_us-gaap_EquityComponentDomain_14c24c57-3034-4218-a374-41841f510d32" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_6fe12aeb-0adf-421f-8c94-8774dea1d1e0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_14c24c57-3034-4218-a374-41841f510d32" xlink:to="loc_us-gaap_CommonStockMember_6fe12aeb-0adf-421f-8c94-8774dea1d1e0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_5d5c4f04-ee8e-4140-af03-c234c1ec1498" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_14c24c57-3034-4218-a374-41841f510d32" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_5d5c4f04-ee8e-4140-af03-c234c1ec1498" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_b7fea85d-f45c-4f56-90da-e9c1cf2c71de" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_8f953dce-0fa4-4230-9da2-e32498993d1e" xlink:to="loc_srt_RangeAxis_b7fea85d-f45c-4f56-90da-e9c1cf2c71de" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_b7fea85d-f45c-4f56-90da-e9c1cf2c71de_default" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_b7fea85d-f45c-4f56-90da-e9c1cf2c71de" xlink:to="loc_srt_RangeMember_b7fea85d-f45c-4f56-90da-e9c1cf2c71de_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_e473355e-f109-4cf5-b0db-3fea1509cf39" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_b7fea85d-f45c-4f56-90da-e9c1cf2c71de" xlink:to="loc_srt_RangeMember_e473355e-f109-4cf5-b0db-3fea1509cf39" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_50b1038f-b6ae-4386-a1b6-907d42746667" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_e473355e-f109-4cf5-b0db-3fea1509cf39" xlink:to="loc_srt_MaximumMember_50b1038f-b6ae-4386-a1b6-907d42746667" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_ff02e1ce-9e60-4b90-9934-757253376aa5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_8f953dce-0fa4-4230-9da2-e32498993d1e" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_ff02e1ce-9e60-4b90-9934-757253376aa5" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_ff02e1ce-9e60-4b90-9934-757253376aa5_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_ff02e1ce-9e60-4b90-9934-757253376aa5" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_ff02e1ce-9e60-4b90-9934-757253376aa5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_07924052-4182-4de0-95f3-ddf094d724bc" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_ff02e1ce-9e60-4b90-9934-757253376aa5" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_07924052-4182-4de0-95f3-ddf094d724bc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_DataPipeMember_a86563b7-3b4e-4ce0-bd61-89633bad6112" xlink:href="rxt-20201231.xsd#rxt_DataPipeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_07924052-4182-4de0-95f3-ddf094d724bc" xlink:to="loc_rxt_DataPipeMember_a86563b7-3b4e-4ce0-bd61-89633bad6112" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.rackspace.com/role/ShareBasedCompensationSettlementofShareBasedAwardsandEmployeeBenefitPlans" xlink:type="simple" xlink:href="rxt-20201231.xsd#ShareBasedCompensationSettlementofShareBasedAwardsandEmployeeBenefitPlans"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/ShareBasedCompensationSettlementofShareBasedAwardsandEmployeeBenefitPlans" xlink:type="extended" id="i7b1648cb577b421baff4949bc618b852_ShareBasedCompensationSettlementofShareBasedAwardsandEmployeeBenefitPlans"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/ShareBasedCompensationSettlementofShareBasedAwardsandEmployeeBenefitPlansTables" xlink:type="simple" xlink:href="rxt-20201231.xsd#ShareBasedCompensationSettlementofShareBasedAwardsandEmployeeBenefitPlansTables"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/ShareBasedCompensationSettlementofShareBasedAwardsandEmployeeBenefitPlansTables" xlink:type="extended" id="i7c384625e3e14de1969826ae4c03ba3b_ShareBasedCompensationSettlementofShareBasedAwardsandEmployeeBenefitPlansTables"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/ShareBasedCompensationSettlementofShareBasedAwardsandEmployeeBenefitPlansNarrativeDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#ShareBasedCompensationSettlementofShareBasedAwardsandEmployeeBenefitPlansNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/ShareBasedCompensationSettlementofShareBasedAwardsandEmployeeBenefitPlansNarrativeDetails" xlink:type="extended" id="i5d51b3fc4d96490bbbc8fe6a04069159_ShareBasedCompensationSettlementofShareBasedAwardsandEmployeeBenefitPlansNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_297758c9-c49a-422d-8e6e-da6f39e1184e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_dff168ec-2f37-4f6d-94f7-06b80922dffd" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_297758c9-c49a-422d-8e6e-da6f39e1184e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_dff168ec-2f37-4f6d-94f7-06b80922dffd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesOutstanding_fa4c348d-5a89-45f3-836e-55f15c457432" xlink:href="rxt-20201231.xsd#rxt_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_297758c9-c49a-422d-8e6e-da6f39e1184e" xlink:to="loc_rxt_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesOutstanding_fa4c348d-5a89-45f3-836e-55f15c457432" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_20e6da88-017a-4176-af64-3d42020f3814" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_297758c9-c49a-422d-8e6e-da6f39e1184e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_20e6da88-017a-4176-af64-3d42020f3814" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_ee81b9d8-3dbc-458b-810d-224393ba683a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_297758c9-c49a-422d-8e6e-da6f39e1184e" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_ee81b9d8-3dbc-458b-810d-224393ba683a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_32d9798b-fc5b-4b8c-947b-eccc4c8f02d8" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_297758c9-c49a-422d-8e6e-da6f39e1184e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_32d9798b-fc5b-4b8c-947b-eccc4c8f02d8" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue_bae4cc27-6cab-43e7-8dbf-555f5bfbcbe4" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_297758c9-c49a-422d-8e6e-da6f39e1184e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue_bae4cc27-6cab-43e7-8dbf-555f5bfbcbe4" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_ede0dbcb-01d8-4ec0-b352-d6267111bfe4" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_297758c9-c49a-422d-8e6e-da6f39e1184e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_ede0dbcb-01d8-4ec0-b352-d6267111bfe4" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions_390b58ad-ffc8-496e-881a-760335cb958b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_297758c9-c49a-422d-8e6e-da6f39e1184e" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions_390b58ad-ffc8-496e-881a-760335cb958b" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_6a8e09f2-2f27-4534-96f3-a108459249ed" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_297758c9-c49a-422d-8e6e-da6f39e1184e" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_6a8e09f2-2f27-4534-96f3-a108459249ed" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriod1_6997f60f-d0e9-405d-b2a3-bc6573932306" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_297758c9-c49a-422d-8e6e-da6f39e1184e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriod1_6997f60f-d0e9-405d-b2a3-bc6573932306" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_7aaf8099-12c9-4bb3-975f-d890bf651f78" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_297758c9-c49a-422d-8e6e-da6f39e1184e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_7aaf8099-12c9-4bb3-975f-d890bf651f78" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueReleased_aad5db34-02c0-4988-8601-9edc71bb9d28" xlink:href="rxt-20201231.xsd#rxt_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueReleased"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_297758c9-c49a-422d-8e6e-da6f39e1184e" xlink:to="loc_rxt_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueReleased_aad5db34-02c0-4988-8601-9edc71bb9d28" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_c93b08c2-f6f6-4c56-95f5-ae88a95dee4d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_297758c9-c49a-422d-8e6e-da6f39e1184e" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_c93b08c2-f6f6-4c56-95f5-ae88a95dee4d" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardPurchasePriceOfCommonStockPercent_0ad91da8-939d-4189-ac57-bb4da0b5c417" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardPurchasePriceOfCommonStockPercent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_297758c9-c49a-422d-8e6e-da6f39e1184e" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardPurchasePriceOfCommonStockPercent_0ad91da8-939d-4189-ac57-bb4da0b5c417" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod_5a335e17-d264-4afc-877f-47fa25c8ecc2" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_297758c9-c49a-422d-8e6e-da6f39e1184e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod_5a335e17-d264-4afc-877f-47fa25c8ecc2" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_848ac1d7-93fa-4dbd-add4-bdfd458bb326" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_297758c9-c49a-422d-8e6e-da6f39e1184e" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_848ac1d7-93fa-4dbd-add4-bdfd458bb326" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardPlanModificationIncrementalCompensationCost_f86c7b63-6462-4a0a-a878-c45cac8060db" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardPlanModificationIncrementalCompensationCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_297758c9-c49a-422d-8e6e-da6f39e1184e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardPlanModificationIncrementalCompensationCost_f86c7b63-6462-4a0a-a878-c45cac8060db" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAcceleratedCompensationCost_18dd79c9-9334-44a5-bbc8-59d49040038c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAcceleratedCompensationCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_297758c9-c49a-422d-8e6e-da6f39e1184e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAcceleratedCompensationCost_18dd79c9-9334-44a5-bbc8-59d49040038c" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsShareBasedLiabilitiesPaid_39da9098-fb06-4db1-9f37-fcd9f4b86e95" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsShareBasedLiabilitiesPaid"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_297758c9-c49a-422d-8e6e-da6f39e1184e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsShareBasedLiabilitiesPaid_39da9098-fb06-4db1-9f37-fcd9f4b86e95" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationCashFlowEffectCashUsedToSettleAwards_1bb4041c-7e07-4f18-bc3e-aac375de78b8" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationCashFlowEffectCashUsedToSettleAwards"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_297758c9-c49a-422d-8e6e-da6f39e1184e" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationCashFlowEffectCashUsedToSettleAwards_1bb4041c-7e07-4f18-bc3e-aac375de78b8" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedContributionPlanCostRecognized_08d37822-b1e4-488e-8a43-c29996e7a5ed" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedContributionPlanCostRecognized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_297758c9-c49a-422d-8e6e-da6f39e1184e" xlink:to="loc_us-gaap_DefinedContributionPlanCostRecognized_08d37822-b1e4-488e-8a43-c29996e7a5ed" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_991b1e62-2cd7-48f2-8b53-410b819c0a91" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_297758c9-c49a-422d-8e6e-da6f39e1184e" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_991b1e62-2cd7-48f2-8b53-410b819c0a91" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_6c194154-8827-4276-baff-b5fabd03527f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_991b1e62-2cd7-48f2-8b53-410b819c0a91" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_6c194154-8827-4276-baff-b5fabd03527f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_6c194154-8827-4276-baff-b5fabd03527f_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_6c194154-8827-4276-baff-b5fabd03527f" xlink:to="loc_us-gaap_EquityComponentDomain_6c194154-8827-4276-baff-b5fabd03527f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_a1da4cf1-ca8a-4c30-b3df-b88e997416ed" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_6c194154-8827-4276-baff-b5fabd03527f" xlink:to="loc_us-gaap_EquityComponentDomain_a1da4cf1-ca8a-4c30-b3df-b88e997416ed" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_fe327bda-5414-491e-b1a2-beba308ca2cf" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_a1da4cf1-ca8a-4c30-b3df-b88e997416ed" xlink:to="loc_us-gaap_CommonStockMember_fe327bda-5414-491e-b1a2-beba308ca2cf" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_489b6a99-6080-47fa-be63-43694e2569b7" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_991b1e62-2cd7-48f2-8b53-410b819c0a91" xlink:to="loc_us-gaap_AwardTypeAxis_489b6a99-6080-47fa-be63-43694e2569b7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_489b6a99-6080-47fa-be63-43694e2569b7_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_489b6a99-6080-47fa-be63-43694e2569b7" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_489b6a99-6080-47fa-be63-43694e2569b7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_84a7a464-6af7-4f7f-bb36-3cc1f33ea15d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_489b6a99-6080-47fa-be63-43694e2569b7" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_84a7a464-6af7-4f7f-bb36-3cc1f33ea15d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_56e79cf8-4e40-4b17-b653-226e1a87f799" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_84a7a464-6af7-4f7f-bb36-3cc1f33ea15d" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_56e79cf8-4e40-4b17-b653-226e1a87f799" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_e23859ea-aaa8-4a15-a322-c840e6a4da26" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_84a7a464-6af7-4f7f-bb36-3cc1f33ea15d" xlink:to="loc_us-gaap_EmployeeStockOptionMember_e23859ea-aaa8-4a15-a322-c840e6a4da26" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_OptionsAndRestrictedStockMember_79997854-0021-4eba-ab4a-33e1d95582b1" xlink:href="rxt-20201231.xsd#rxt_OptionsAndRestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_84a7a464-6af7-4f7f-bb36-3cc1f33ea15d" xlink:to="loc_rxt_OptionsAndRestrictedStockMember_79997854-0021-4eba-ab4a-33e1d95582b1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockMember_27e3c44c-4592-46e7-8659-d15457ca5039" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EmployeeStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_84a7a464-6af7-4f7f-bb36-3cc1f33ea15d" xlink:to="loc_us-gaap_EmployeeStockMember_27e3c44c-4592-46e7-8659-d15457ca5039" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PerformanceSharesMember_4ffaafe9-0687-4751-b2aa-3e9e66dd569e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PerformanceSharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_84a7a464-6af7-4f7f-bb36-3cc1f33ea15d" xlink:to="loc_us-gaap_PerformanceSharesMember_4ffaafe9-0687-4751-b2aa-3e9e66dd569e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_8b849dfc-0e32-4ea3-8793-913117b04022" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_84a7a464-6af7-4f7f-bb36-3cc1f33ea15d" xlink:to="loc_us-gaap_RestrictedStockMember_8b849dfc-0e32-4ea3-8793-913117b04022" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis_b842e7f5-93ce-428d-b65c-1e5c661c361d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PlanNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_991b1e62-2cd7-48f2-8b53-410b819c0a91" xlink:to="loc_us-gaap_PlanNameAxis_b842e7f5-93ce-428d-b65c-1e5c661c361d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_b842e7f5-93ce-428d-b65c-1e5c661c361d_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_b842e7f5-93ce-428d-b65c-1e5c661c361d" xlink:to="loc_us-gaap_PlanNameDomain_b842e7f5-93ce-428d-b65c-1e5c661c361d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_e03464ec-3f66-453e-b48f-4e7664185976" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_b842e7f5-93ce-428d-b65c-1e5c661c361d" xlink:to="loc_us-gaap_PlanNameDomain_e03464ec-3f66-453e-b48f-4e7664185976" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_A2017IncentivePlanMember_e2c3c027-5811-492c-80a2-0cf0fe367c9e" xlink:href="rxt-20201231.xsd#rxt_A2017IncentivePlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_e03464ec-3f66-453e-b48f-4e7664185976" xlink:to="loc_rxt_A2017IncentivePlanMember_e2c3c027-5811-492c-80a2-0cf0fe367c9e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_A2020IncentivePlanMember_9acec313-ca53-4b85-893a-ad3a64741efb" xlink:href="rxt-20201231.xsd#rxt_A2020IncentivePlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_e03464ec-3f66-453e-b48f-4e7664185976" xlink:to="loc_rxt_A2020IncentivePlanMember_9acec313-ca53-4b85-893a-ad3a64741efb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_EmployeeStockPurchasePlanMember_5e174afb-39bc-4478-81fd-bf39e75ad45a" xlink:href="rxt-20201231.xsd#rxt_EmployeeStockPurchasePlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_e03464ec-3f66-453e-b48f-4e7664185976" xlink:to="loc_rxt_EmployeeStockPurchasePlanMember_5e174afb-39bc-4478-81fd-bf39e75ad45a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_TitleOfIndividualAxis_b9ded4f8-aa4b-42fd-b031-878865380397" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_TitleOfIndividualAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_991b1e62-2cd7-48f2-8b53-410b819c0a91" xlink:to="loc_srt_TitleOfIndividualAxis_b9ded4f8-aa4b-42fd-b031-878865380397" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_b9ded4f8-aa4b-42fd-b031-878865380397_default" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_TitleOfIndividualWithRelationshipToEntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_TitleOfIndividualAxis_b9ded4f8-aa4b-42fd-b031-878865380397" xlink:to="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_b9ded4f8-aa4b-42fd-b031-878865380397_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_d311c1cc-caf8-4bbb-bd34-2084378b37e2" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_TitleOfIndividualWithRelationshipToEntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_TitleOfIndividualAxis_b9ded4f8-aa4b-42fd-b031-878865380397" xlink:to="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_d311c1cc-caf8-4bbb-bd34-2084378b37e2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ExecutiveOfficerMember_a7d70358-7c83-4c56-993f-c203d50d1ac6" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ExecutiveOfficerMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_d311c1cc-caf8-4bbb-bd34-2084378b37e2" xlink:to="loc_srt_ExecutiveOfficerMember_a7d70358-7c83-4c56-993f-c203d50d1ac6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_DirectorMember_c92bf513-f5b2-4d28-af67-22f1b7c98af6" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_DirectorMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_d311c1cc-caf8-4bbb-bd34-2084378b37e2" xlink:to="loc_srt_DirectorMember_c92bf513-f5b2-4d28-af67-22f1b7c98af6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsidiarySaleOfStockAxis_fefdfe60-4ff4-48a7-8ab9-746b1b5239da" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsidiarySaleOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_991b1e62-2cd7-48f2-8b53-410b819c0a91" xlink:to="loc_us-gaap_SubsidiarySaleOfStockAxis_fefdfe60-4ff4-48a7-8ab9-746b1b5239da" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_fefdfe60-4ff4-48a7-8ab9-746b1b5239da_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_fefdfe60-4ff4-48a7-8ab9-746b1b5239da" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_fefdfe60-4ff4-48a7-8ab9-746b1b5239da_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_a3d34b47-1bb0-479d-9720-fd1be1522000" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_fefdfe60-4ff4-48a7-8ab9-746b1b5239da" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_a3d34b47-1bb0-479d-9720-fd1be1522000" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IPOMember_0f43ad90-e326-450d-80d9-c226cd19a5af" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IPOMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SaleOfStockNameOfTransactionDomain_a3d34b47-1bb0-479d-9720-fd1be1522000" xlink:to="loc_us-gaap_IPOMember_0f43ad90-e326-450d-80d9-c226cd19a5af" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_6f2d560d-e265-4008-b2f9-4d652e07bd2c" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_991b1e62-2cd7-48f2-8b53-410b819c0a91" xlink:to="loc_srt_RangeAxis_6f2d560d-e265-4008-b2f9-4d652e07bd2c" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_6f2d560d-e265-4008-b2f9-4d652e07bd2c_default" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_6f2d560d-e265-4008-b2f9-4d652e07bd2c" xlink:to="loc_srt_RangeMember_6f2d560d-e265-4008-b2f9-4d652e07bd2c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_95b35a44-14ef-4895-8a2c-e32f33da1b04" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_6f2d560d-e265-4008-b2f9-4d652e07bd2c" xlink:to="loc_srt_RangeMember_95b35a44-14ef-4895-8a2c-e32f33da1b04" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_02285d39-3916-4e1d-bdc3-cfb9299caac8" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_95b35a44-14ef-4895-8a2c-e32f33da1b04" xlink:to="loc_srt_MinimumMember_02285d39-3916-4e1d-bdc3-cfb9299caac8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_11318930-3fa8-4296-b56d-2c8be7705a7a" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_95b35a44-14ef-4895-8a2c-e32f33da1b04" xlink:to="loc_srt_MaximumMember_11318930-3fa8-4296-b56d-2c8be7705a7a" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.rackspace.com/role/ShareBasedCompensationSettlementofShareBasedAwardsandEmployeeBenefitPlansEquityAwardsOutstandingDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#ShareBasedCompensationSettlementofShareBasedAwardsandEmployeeBenefitPlansEquityAwardsOutstandingDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/ShareBasedCompensationSettlementofShareBasedAwardsandEmployeeBenefitPlansEquityAwardsOutstandingDetails" xlink:type="extended" id="i2a13d227d89142f680f3a7f3390ada8a_ShareBasedCompensationSettlementofShareBasedAwardsandEmployeeBenefitPlansEquityAwardsOutstandingDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_47d5f07f-c8b9-4a46-9a5a-76cb8ecba55a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_af6423d4-4f7c-4edf-9f21-3a10b9ab1cb3" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_47d5f07f-c8b9-4a46-9a5a-76cb8ecba55a" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_af6423d4-4f7c-4edf-9f21-3a10b9ab1cb3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_0d231792-4b86-4ddf-bfa2-970a245e5511" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_47d5f07f-c8b9-4a46-9a5a-76cb8ecba55a" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_0d231792-4b86-4ddf-bfa2-970a245e5511" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAndEquityInstrumentsOtherThanOptionsOutstandingNumber_c4411979-5d13-4488-afca-e473b99ad937" xlink:href="rxt-20201231.xsd#rxt_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAndEquityInstrumentsOtherThanOptionsOutstandingNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_47d5f07f-c8b9-4a46-9a5a-76cb8ecba55a" xlink:to="loc_rxt_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAndEquityInstrumentsOtherThanOptionsOutstandingNumber_c4411979-5d13-4488-afca-e473b99ad937" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_f43d6315-fb1e-4240-a2ad-7293530a3c65" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_47d5f07f-c8b9-4a46-9a5a-76cb8ecba55a" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_f43d6315-fb1e-4240-a2ad-7293530a3c65" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_0a33900f-96d3-43d9-bf1f-61fcc7e3c9c3" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_f43d6315-fb1e-4240-a2ad-7293530a3c65" xlink:to="loc_us-gaap_AwardTypeAxis_0a33900f-96d3-43d9-bf1f-61fcc7e3c9c3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_0a33900f-96d3-43d9-bf1f-61fcc7e3c9c3_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_0a33900f-96d3-43d9-bf1f-61fcc7e3c9c3" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_0a33900f-96d3-43d9-bf1f-61fcc7e3c9c3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_61ed453d-4d08-48b8-977b-c1fe9885c15d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_0a33900f-96d3-43d9-bf1f-61fcc7e3c9c3" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_61ed453d-4d08-48b8-977b-c1fe9885c15d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_e2226151-b39a-4861-8eb5-fa76d77b28f1" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_61ed453d-4d08-48b8-977b-c1fe9885c15d" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_e2226151-b39a-4861-8eb5-fa76d77b28f1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_2fddb340-6033-49b2-b12f-26d7e8755958" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_61ed453d-4d08-48b8-977b-c1fe9885c15d" xlink:to="loc_us-gaap_EmployeeStockOptionMember_2fddb340-6033-49b2-b12f-26d7e8755958" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.rackspace.com/role/ShareBasedCompensationSettlementofShareBasedAwardsandEmployeeBenefitPlansStockOptionActivityDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#ShareBasedCompensationSettlementofShareBasedAwardsandEmployeeBenefitPlansStockOptionActivityDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/ShareBasedCompensationSettlementofShareBasedAwardsandEmployeeBenefitPlansStockOptionActivityDetails" xlink:type="extended" id="ib0c7586759f6477d8beedffe1ceaaaa1_ShareBasedCompensationSettlementofShareBasedAwardsandEmployeeBenefitPlansStockOptionActivityDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1028b66f-fe27-4243-886e-e87ae1e35dd4" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_a23e4215-6bc0-4660-be8a-e5e6f7055259" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1028b66f-fe27-4243-886e-e87ae1e35dd4" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_a23e4215-6bc0-4660-be8a-e5e6f7055259" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_81cb0d61-feb3-4f5e-8e84-5dc250597280" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_a23e4215-6bc0-4660-be8a-e5e6f7055259" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_81cb0d61-feb3-4f5e-8e84-5dc250597280" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_6cf2686d-5c8d-4035-a388-1e5fe78fdd13" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_a23e4215-6bc0-4660-be8a-e5e6f7055259" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_6cf2686d-5c8d-4035-a388-1e5fe78fdd13" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_800f1165-8a44-4a9a-9d27-d36b39dac6e2" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_a23e4215-6bc0-4660-be8a-e5e6f7055259" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_800f1165-8a44-4a9a-9d27-d36b39dac6e2" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod_1c762dac-102a-4ca9-bb23-d81ef3694b77" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_a23e4215-6bc0-4660-be8a-e5e6f7055259" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod_1c762dac-102a-4ca9-bb23-d81ef3694b77" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod_4249067f-71e8-4c24-b19d-3bc95a1b85a6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_a23e4215-6bc0-4660-be8a-e5e6f7055259" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod_4249067f-71e8-4c24-b19d-3bc95a1b85a6" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_8f16fcc5-99a6-4617-9397-3c6758f18f79" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber_d5bb1324-9018-4bb5-819e-df9bc7a80998" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_a23e4215-6bc0-4660-be8a-e5e6f7055259" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber_d5bb1324-9018-4bb5-819e-df9bc7a80998" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableNumber_61f1224c-0ff1-4eaa-963b-feecb9ac2922" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_a23e4215-6bc0-4660-be8a-e5e6f7055259" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableNumber_61f1224c-0ff1-4eaa-963b-feecb9ac2922" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_b0ead45e-d8eb-4308-b4b2-92aaf819acc6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1028b66f-fe27-4243-886e-e87ae1e35dd4" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_b0ead45e-d8eb-4308-b4b2-92aaf819acc6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_d8b388f5-9267-42ad-847e-3cbb31e4ebbc" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_b0ead45e-d8eb-4308-b4b2-92aaf819acc6" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_d8b388f5-9267-42ad-847e-3cbb31e4ebbc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice_fdad60d5-9b73-4c37-b7be-6720c38955ab" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_b0ead45e-d8eb-4308-b4b2-92aaf819acc6" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice_fdad60d5-9b73-4c37-b7be-6720c38955ab" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice_fd11fd1a-0f40-4d72-9e29-ab2fa8951fd8" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_b0ead45e-d8eb-4308-b4b2-92aaf819acc6" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice_fd11fd1a-0f40-4d72-9e29-ab2fa8951fd8" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice_76a1086d-ca81-4f37-bfa9-f62e64ee17b7" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_b0ead45e-d8eb-4308-b4b2-92aaf819acc6" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice_76a1086d-ca81-4f37-bfa9-f62e64ee17b7" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExpirationsInPeriodWeightedAverageExercisePrice_f3a52046-dfe8-47b4-b636-8d50199f33ef" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExpirationsInPeriodWeightedAverageExercisePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_b0ead45e-d8eb-4308-b4b2-92aaf819acc6" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExpirationsInPeriodWeightedAverageExercisePrice_f3a52046-dfe8-47b4-b636-8d50199f33ef" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_48627419-0d4a-48cf-b79c-086b382307e5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice_c29ebf25-31dc-44ca-b6cc-646c36884c67" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_b0ead45e-d8eb-4308-b4b2-92aaf819acc6" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice_c29ebf25-31dc-44ca-b6cc-646c36884c67" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableWeightedAverageExercisePrice_6fe5bcf5-67a5-4671-b9c1-e610f57e3f81" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableWeightedAverageExercisePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_b0ead45e-d8eb-4308-b4b2-92aaf819acc6" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableWeightedAverageExercisePrice_6fe5bcf5-67a5-4671-b9c1-e610f57e3f81" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract_030ea48f-9ae9-4aa1-aa1b-7165dc30cae5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1028b66f-fe27-4243-886e-e87ae1e35dd4" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract_030ea48f-9ae9-4aa1-aa1b-7165dc30cae5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2_54f19137-7fb4-4a69-b1b5-0419dc6379e0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract_030ea48f-9ae9-4aa1-aa1b-7165dc30cae5" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2_54f19137-7fb4-4a69-b1b5-0419dc6379e0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1_4276fcb3-6d51-43d6-bc11-d9eccb0c7573" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract_030ea48f-9ae9-4aa1-aa1b-7165dc30cae5" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1_4276fcb3-6d51-43d6-bc11-d9eccb0c7573" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestExercisableWeightedAverageRemainingContractualTerm1_200980fd-4600-40ee-b298-8592ca529074" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestExercisableWeightedAverageRemainingContractualTerm1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract_030ea48f-9ae9-4aa1-aa1b-7165dc30cae5" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestExercisableWeightedAverageRemainingContractualTerm1_200980fd-4600-40ee-b298-8592ca529074" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue_525aad13-9b89-4f5e-add9-1e11eb213c74" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract_030ea48f-9ae9-4aa1-aa1b-7165dc30cae5" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue_525aad13-9b89-4f5e-add9-1e11eb213c74" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1_5ece0d0e-395a-4730-aca8-11228ea3de97" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract_030ea48f-9ae9-4aa1-aa1b-7165dc30cae5" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1_5ece0d0e-395a-4730-aca8-11228ea3de97" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableAggregateIntrinsicValue_0998a86a-bc44-481a-a65b-9a8035071bf5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableAggregateIntrinsicValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract_030ea48f-9ae9-4aa1-aa1b-7165dc30cae5" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableAggregateIntrinsicValue_0998a86a-bc44-481a-a65b-9a8035071bf5" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_9aef558e-d527-43c1-93df-3a1962a268cd" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1028b66f-fe27-4243-886e-e87ae1e35dd4" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_9aef558e-d527-43c1-93df-3a1962a268cd" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_2d60aa79-fc0a-4f2e-a891-2065dee7e511" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_9aef558e-d527-43c1-93df-3a1962a268cd" xlink:to="loc_us-gaap_AwardTypeAxis_2d60aa79-fc0a-4f2e-a891-2065dee7e511" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_2d60aa79-fc0a-4f2e-a891-2065dee7e511_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_2d60aa79-fc0a-4f2e-a891-2065dee7e511" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_2d60aa79-fc0a-4f2e-a891-2065dee7e511_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_416ffbe6-98cf-4e8d-bc38-48aba23f91fd" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_2d60aa79-fc0a-4f2e-a891-2065dee7e511" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_416ffbe6-98cf-4e8d-bc38-48aba23f91fd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_057ae5b1-c158-4c9e-9bab-dc4c0ca6dad5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_416ffbe6-98cf-4e8d-bc38-48aba23f91fd" xlink:to="loc_us-gaap_EmployeeStockOptionMember_057ae5b1-c158-4c9e-9bab-dc4c0ca6dad5" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.rackspace.com/role/ShareBasedCompensationSettlementofShareBasedAwardsandEmployeeBenefitPlansFairValueAssumptionsDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#ShareBasedCompensationSettlementofShareBasedAwardsandEmployeeBenefitPlansFairValueAssumptionsDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/ShareBasedCompensationSettlementofShareBasedAwardsandEmployeeBenefitPlansFairValueAssumptionsDetails" xlink:type="extended" id="iea53f7c05bdd4187ade3eef195d62911_ShareBasedCompensationSettlementofShareBasedAwardsandEmployeeBenefitPlansFairValueAssumptionsDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_3edc4237-5361-4a31-8642-8bac24582ffa" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRateMinimum_a2471c16-ebda-4ca5-a453-de77755842d6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRateMinimum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_3edc4237-5361-4a31-8642-8bac24582ffa" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRateMinimum_a2471c16-ebda-4ca5-a453-de77755842d6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRateMaximum_516f3252-ea5c-41a9-9b1b-0c1315596042" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRateMaximum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_3edc4237-5361-4a31-8642-8bac24582ffa" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRateMaximum_516f3252-ea5c-41a9-9b1b-0c1315596042" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_eaa66d0c-6f91-40b2-a85b-22abb0ad6fc5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_3edc4237-5361-4a31-8642-8bac24582ffa" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_eaa66d0c-6f91-40b2-a85b-22abb0ad6fc5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate_6512dae8-384e-4f6c-90c0-ab11c9aeb26e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_3edc4237-5361-4a31-8642-8bac24582ffa" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate_6512dae8-384e-4f6c-90c0-ab11c9aeb26e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateMinimum_9a972b0a-b3e4-469c-a175-703e02ca61f6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateMinimum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_3edc4237-5361-4a31-8642-8bac24582ffa" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateMinimum_9a972b0a-b3e4-469c-a175-703e02ca61f6" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateMaximum_54fc7784-0bf1-42fa-a41e-4990e7be971f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateMaximum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_3edc4237-5361-4a31-8642-8bac24582ffa" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateMaximum_54fc7784-0bf1-42fa-a41e-4990e7be971f" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_26d3f852-6cef-4ea2-bbfc-cd5eb19786a9" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_3edc4237-5361-4a31-8642-8bac24582ffa" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_26d3f852-6cef-4ea2-bbfc-cd5eb19786a9" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_821e8e3c-8257-4010-829f-8174338134ad" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_3edc4237-5361-4a31-8642-8bac24582ffa" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_821e8e3c-8257-4010-829f-8174338134ad" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_9a0abc05-c488-4993-b81a-501e8c6323cb" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_821e8e3c-8257-4010-829f-8174338134ad" xlink:to="loc_srt_RangeAxis_9a0abc05-c488-4993-b81a-501e8c6323cb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_9a0abc05-c488-4993-b81a-501e8c6323cb_default" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_9a0abc05-c488-4993-b81a-501e8c6323cb" xlink:to="loc_srt_RangeMember_9a0abc05-c488-4993-b81a-501e8c6323cb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_654fc207-16d9-46c8-9c0f-0ea24bf824be" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_9a0abc05-c488-4993-b81a-501e8c6323cb" xlink:to="loc_srt_RangeMember_654fc207-16d9-46c8-9c0f-0ea24bf824be" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_bebde736-4749-48dc-a7ea-5a5656c81c6f" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_654fc207-16d9-46c8-9c0f-0ea24bf824be" xlink:to="loc_srt_MinimumMember_bebde736-4749-48dc-a7ea-5a5656c81c6f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_f2f35f88-fd0a-4b1e-a396-0bb3dd394dbc" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_654fc207-16d9-46c8-9c0f-0ea24bf824be" xlink:to="loc_srt_MaximumMember_f2f35f88-fd0a-4b1e-a396-0bb3dd394dbc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_f0e4dc8f-6178-4857-9d4a-30b11d1290ad" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_821e8e3c-8257-4010-829f-8174338134ad" xlink:to="loc_us-gaap_AwardTypeAxis_f0e4dc8f-6178-4857-9d4a-30b11d1290ad" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_f0e4dc8f-6178-4857-9d4a-30b11d1290ad_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_f0e4dc8f-6178-4857-9d4a-30b11d1290ad" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_f0e4dc8f-6178-4857-9d4a-30b11d1290ad_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_c783a303-02ce-447f-af57-3c5343699a24" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_f0e4dc8f-6178-4857-9d4a-30b11d1290ad" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_c783a303-02ce-447f-af57-3c5343699a24" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_1d499e7c-3472-4eb5-8347-ebacdda570fe" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_c783a303-02ce-447f-af57-3c5343699a24" xlink:to="loc_us-gaap_EmployeeStockOptionMember_1d499e7c-3472-4eb5-8347-ebacdda570fe" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.rackspace.com/role/ShareBasedCompensationSettlementofShareBasedAwardsandEmployeeBenefitPlansRestrictedStockActivityDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#ShareBasedCompensationSettlementofShareBasedAwardsandEmployeeBenefitPlansRestrictedStockActivityDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/ShareBasedCompensationSettlementofShareBasedAwardsandEmployeeBenefitPlansRestrictedStockActivityDetails" xlink:type="extended" id="i479e8216ddba409599a146c634726d5c_ShareBasedCompensationSettlementofShareBasedAwardsandEmployeeBenefitPlansRestrictedStockActivityDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_3ec9d748-cd54-49bb-9f33-f1243b2ef970" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingRollForward_128521d4-1d3e-40c7-9d27-aa44155b26ee" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_3ec9d748-cd54-49bb-9f33-f1243b2ef970" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingRollForward_128521d4-1d3e-40c7-9d27-aa44155b26ee" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_db9a90eb-303d-4919-8060-1a9514366725" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingRollForward_128521d4-1d3e-40c7-9d27-aa44155b26ee" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_db9a90eb-303d-4919-8060-1a9514366725" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_ba184112-b36d-4e7f-8270-377e5d73b328" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingRollForward_128521d4-1d3e-40c7-9d27-aa44155b26ee" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_ba184112-b36d-4e7f-8270-377e5d73b328" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsReleasedInPeriod_0a807a8e-79e5-457d-a643-79f9a645b806" xlink:href="rxt-20201231.xsd#rxt_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsReleasedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingRollForward_128521d4-1d3e-40c7-9d27-aa44155b26ee" xlink:to="loc_rxt_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsReleasedInPeriod_0a807a8e-79e5-457d-a643-79f9a645b806" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_02115d93-7dc2-486d-9729-beb7f127321c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingRollForward_128521d4-1d3e-40c7-9d27-aa44155b26ee" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_02115d93-7dc2-486d-9729-beb7f127321c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_57043543-c0f1-4168-91f8-c6beeffda4b3" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentExpectedToVest_811678a7-1f08-4146-a164-19fa6007d381" xlink:href="rxt-20201231.xsd#rxt_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentExpectedToVest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingRollForward_128521d4-1d3e-40c7-9d27-aa44155b26ee" xlink:to="loc_rxt_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentExpectedToVest_811678a7-1f08-4146-a164-19fa6007d381" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_0da8c12a-488b-4284-816e-e9e91bbfc5d0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_3ec9d748-cd54-49bb-9f33-f1243b2ef970" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_0da8c12a-488b-4284-816e-e9e91bbfc5d0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_d9a12259-b9ea-4aff-ba81-5b5134601a60" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_0da8c12a-488b-4284-816e-e9e91bbfc5d0" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_d9a12259-b9ea-4aff-ba81-5b5134601a60" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_d1ca3f9f-4fa3-4e9a-bc1e-65b5909757da" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_0da8c12a-488b-4284-816e-e9e91bbfc5d0" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_d1ca3f9f-4fa3-4e9a-bc1e-65b5909757da" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsReleasedWeightedAverageGrantDateFairValue_3faef6e5-1873-45e6-959f-bf9d0081371e" xlink:href="rxt-20201231.xsd#rxt_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsReleasedWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_0da8c12a-488b-4284-816e-e9e91bbfc5d0" xlink:to="loc_rxt_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsReleasedWeightedAverageGrantDateFairValue_3faef6e5-1873-45e6-959f-bf9d0081371e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_d67f701a-c1ba-4efe-8ebc-06473d64df76" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_0da8c12a-488b-4284-816e-e9e91bbfc5d0" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_d67f701a-c1ba-4efe-8ebc-06473d64df76" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_c85a332b-ac39-4f8f-8514-457ba0a6fcad" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsExpectedToVestWeightedAverageGrantDateFairValue_3c6fc8c6-2bf5-4178-93ca-36b36c06a308" xlink:href="rxt-20201231.xsd#rxt_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsExpectedToVestWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_0da8c12a-488b-4284-816e-e9e91bbfc5d0" xlink:to="loc_rxt_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsExpectedToVestWeightedAverageGrantDateFairValue_3c6fc8c6-2bf5-4178-93ca-36b36c06a308" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_6fc759cd-a196-4254-9fa0-9e0d62786c7e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_3ec9d748-cd54-49bb-9f33-f1243b2ef970" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_6fc759cd-a196-4254-9fa0-9e0d62786c7e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_b1845d6f-c8c3-4175-ad11-df9510dd8ce6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_6fc759cd-a196-4254-9fa0-9e0d62786c7e" xlink:to="loc_us-gaap_AwardTypeAxis_b1845d6f-c8c3-4175-ad11-df9510dd8ce6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_b1845d6f-c8c3-4175-ad11-df9510dd8ce6_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_b1845d6f-c8c3-4175-ad11-df9510dd8ce6" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_b1845d6f-c8c3-4175-ad11-df9510dd8ce6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_6b1909b6-941b-4571-be67-cc8d31715140" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_b1845d6f-c8c3-4175-ad11-df9510dd8ce6" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_6b1909b6-941b-4571-be67-cc8d31715140" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_177db447-7714-4075-a1e1-020327ccae62" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_6b1909b6-941b-4571-be67-cc8d31715140" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_177db447-7714-4075-a1e1-020327ccae62" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.rackspace.com/role/ShareBasedCompensationSettlementofShareBasedAwardsandEmployeeBenefitPlansSharebasedCompensationExpenseRecognizedDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#ShareBasedCompensationSettlementofShareBasedAwardsandEmployeeBenefitPlansSharebasedCompensationExpenseRecognizedDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/ShareBasedCompensationSettlementofShareBasedAwardsandEmployeeBenefitPlansSharebasedCompensationExpenseRecognizedDetails" xlink:type="extended" id="ife5b04d4c7ec4af89dab8c4cbf940a71_ShareBasedCompensationSettlementofShareBasedAwardsandEmployeeBenefitPlansSharebasedCompensationExpenseRecognizedDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_bfa36fcd-9bab-42be-8bef-1c2053ab4366" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_9341cb02-b051-45f8-85d7-79f75786294f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_bfa36fcd-9bab-42be-8bef-1c2053ab4366" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_9341cb02-b051-45f8-85d7-79f75786294f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense_107a1c86-d6b5-4c3f-9c6a-b3bdb9a99c17" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_bfa36fcd-9bab-42be-8bef-1c2053ab4366" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense_107a1c86-d6b5-4c3f-9c6a-b3bdb9a99c17" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpenseNetOfTax_b443dea7-4a66-4f79-b054-80da47d4cea8" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AllocatedShareBasedCompensationExpenseNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_bfa36fcd-9bab-42be-8bef-1c2053ab4366" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpenseNetOfTax_b443dea7-4a66-4f79-b054-80da47d4cea8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_58d125b0-8f18-431e-a64a-23f7826cdc92" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_bfa36fcd-9bab-42be-8bef-1c2053ab4366" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_58d125b0-8f18-431e-a64a-23f7826cdc92" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_852eb885-2ecb-4eae-9dd7-6d2b14f7c3b4" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeStatementLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_58d125b0-8f18-431e-a64a-23f7826cdc92" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_852eb885-2ecb-4eae-9dd7-6d2b14f7c3b4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_852eb885-2ecb-4eae-9dd7-6d2b14f7c3b4_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_852eb885-2ecb-4eae-9dd7-6d2b14f7c3b4" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_852eb885-2ecb-4eae-9dd7-6d2b14f7c3b4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_b86d9752-f6f4-4250-8829-72c2e97b0dd8" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_852eb885-2ecb-4eae-9dd7-6d2b14f7c3b4" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_b86d9752-f6f4-4250-8829-72c2e97b0dd8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfSalesMember_14d44df9-edab-4bc9-bbf1-1062e5b62108" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CostOfSalesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_b86d9752-f6f4-4250-8829-72c2e97b0dd8" xlink:to="loc_us-gaap_CostOfSalesMember_14d44df9-edab-4bc9-bbf1-1062e5b62108" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpensesMember_0fea6113-b790-4852-887b-a9398ada6dfc" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SellingGeneralAndAdministrativeExpensesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_b86d9752-f6f4-4250-8829-72c2e97b0dd8" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpensesMember_0fea6113-b790-4852-887b-a9398ada6dfc" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.rackspace.com/role/ShareBasedCompensationSettlementofShareBasedAwardsandEmployeeBenefitPlansPaymentActivityDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#ShareBasedCompensationSettlementofShareBasedAwardsandEmployeeBenefitPlansPaymentActivityDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/ShareBasedCompensationSettlementofShareBasedAwardsandEmployeeBenefitPlansPaymentActivityDetails" xlink:type="extended" id="i01947bb45ab74dec9b595e0ebaa14546_ShareBasedCompensationSettlementofShareBasedAwardsandEmployeeBenefitPlansPaymentActivityDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_114fb69c-72ff-43fe-8b17-80a3a67782a8" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_cd162966-583d-466d-b61f-90214951ed8d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_114fb69c-72ff-43fe-8b17-80a3a67782a8" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_cd162966-583d-466d-b61f-90214951ed8d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_6565f362-c1c0-46b6-9602-af82113e9cd0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_114fb69c-72ff-43fe-8b17-80a3a67782a8" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_6565f362-c1c0-46b6-9602-af82113e9cd0" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_1a865cf5-4ab1-42c6-aeff-c29aab3aa13e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_6565f362-c1c0-46b6-9602-af82113e9cd0" xlink:to="loc_us-gaap_AwardTypeAxis_1a865cf5-4ab1-42c6-aeff-c29aab3aa13e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1a865cf5-4ab1-42c6-aeff-c29aab3aa13e_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_1a865cf5-4ab1-42c6-aeff-c29aab3aa13e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1a865cf5-4ab1-42c6-aeff-c29aab3aa13e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_c47d775e-01f9-465f-800e-b674252c8d4a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_1a865cf5-4ab1-42c6-aeff-c29aab3aa13e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_c47d775e-01f9-465f-800e-b674252c8d4a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_357d5e3e-b573-4a65-a8bc-fb6596d8fdd5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_c47d775e-01f9-465f-800e-b674252c8d4a" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_357d5e3e-b573-4a65-a8bc-fb6596d8fdd5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_d699c372-d612-43c3-bca9-3860cd17624f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeStatementLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_6565f362-c1c0-46b6-9602-af82113e9cd0" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_d699c372-d612-43c3-bca9-3860cd17624f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_d699c372-d612-43c3-bca9-3860cd17624f_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_d699c372-d612-43c3-bca9-3860cd17624f" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_d699c372-d612-43c3-bca9-3860cd17624f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_c33270f6-638f-4dc1-b4b8-e95abe8d3ad4" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_d699c372-d612-43c3-bca9-3860cd17624f" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_c33270f6-638f-4dc1-b4b8-e95abe8d3ad4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfSalesMember_c1c1bbf2-23e6-44b2-bb3b-ae86f3dc08c4" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CostOfSalesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_c33270f6-638f-4dc1-b4b8-e95abe8d3ad4" xlink:to="loc_us-gaap_CostOfSalesMember_c1c1bbf2-23e6-44b2-bb3b-ae86f3dc08c4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpensesMember_fb87b218-2df0-458e-b108-10f672edec50" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SellingGeneralAndAdministrativeExpensesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_c33270f6-638f-4dc1-b4b8-e95abe8d3ad4" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpensesMember_fb87b218-2df0-458e-b108-10f672edec50" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.rackspace.com/role/Taxes" xlink:type="simple" xlink:href="rxt-20201231.xsd#Taxes"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/Taxes" xlink:type="extended" id="i71e75c3bcf704f04bbac70cde93b753e_Taxes"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/IncomeTaxesTables" xlink:type="simple" xlink:href="rxt-20201231.xsd#IncomeTaxesTables"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/IncomeTaxesTables" xlink:type="extended" id="i5b0fdb0f4df34926bf90aa632763d5a3_IncomeTaxesTables"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/TaxesBenefitforIncomeTaxesDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#TaxesBenefitforIncomeTaxesDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/TaxesBenefitforIncomeTaxesDetails" xlink:type="extended" id="ib0c239626a66439ebef187e262ec3460_TaxesBenefitforIncomeTaxesDetails"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/TaxesLossBeforeIncomeTaxesDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#TaxesLossBeforeIncomeTaxesDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/TaxesLossBeforeIncomeTaxesDetails" xlink:type="extended" id="i88990c2493a64a939ff5205e78811484_TaxesLossBeforeIncomeTaxesDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxContingencyLineItems_ec9c3659-f8df-456c-905b-7d4c250efef6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxContingencyLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_08dff79f-0f35-47ef-aafe-a75e8db0ee44" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_ec9c3659-f8df-456c-905b-7d4c250efef6" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_08dff79f-0f35-47ef-aafe-a75e8db0ee44" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxContingencyTable_0c3d3472-2e8e-445a-99c6-c125df7dcabd" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxContingencyTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_ec9c3659-f8df-456c-905b-7d4c250efef6" xlink:to="loc_us-gaap_IncomeTaxContingencyTable_0c3d3472-2e8e-445a-99c6-c125df7dcabd" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityAxis_6069dd7b-6fad-44b1-806e-e16f9ea128fc" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxAuthorityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeTaxContingencyTable_0c3d3472-2e8e-445a-99c6-c125df7dcabd" xlink:to="loc_us-gaap_IncomeTaxAuthorityAxis_6069dd7b-6fad-44b1-806e-e16f9ea128fc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_6069dd7b-6fad-44b1-806e-e16f9ea128fc_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_6069dd7b-6fad-44b1-806e-e16f9ea128fc" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_6069dd7b-6fad-44b1-806e-e16f9ea128fc_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_ef0dbfc5-016f-40fc-9217-edd44c877087" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_6069dd7b-6fad-44b1-806e-e16f9ea128fc" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_ef0dbfc5-016f-40fc-9217-edd44c877087" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticCountryMember_77cccce6-2fa4-4743-960c-6ec87960208e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DomesticCountryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_ef0dbfc5-016f-40fc-9217-edd44c877087" xlink:to="loc_us-gaap_DomesticCountryMember_77cccce6-2fa4-4743-960c-6ec87960208e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignCountryMember_40d8d317-54f0-4a96-b98e-f47275189be0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ForeignCountryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_ef0dbfc5-016f-40fc-9217-edd44c877087" xlink:to="loc_us-gaap_ForeignCountryMember_40d8d317-54f0-4a96-b98e-f47275189be0" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.rackspace.com/role/TaxesNarrativeDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#TaxesNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/TaxesNarrativeDetails" xlink:type="extended" id="i73d5fa0d9ed04902904fea4608dc9141_TaxesNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TaxCreditCarryforwardLineItems_1e59c0d2-5437-419d-a074-47051cffef46" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TaxCreditCarryforwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetsOperatingLossCarryforwards_366d25a5-f181-470a-8a0a-9f1ae6eba2a6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxAssetsOperatingLossCarryforwards"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TaxCreditCarryforwardLineItems_1e59c0d2-5437-419d-a074-47051cffef46" xlink:to="loc_us-gaap_DeferredTaxAssetsOperatingLossCarryforwards_366d25a5-f181-470a-8a0a-9f1ae6eba2a6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsSubjectToExpiration_76820c88-adf7-4959-8552-70586891de08" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsSubjectToExpiration"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TaxCreditCarryforwardLineItems_1e59c0d2-5437-419d-a074-47051cffef46" xlink:to="loc_us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsSubjectToExpiration_76820c88-adf7-4959-8552-70586891de08" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsNotSubjectToExpiration_48ea88d2-71c7-4537-bef9-62830a425f66" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsNotSubjectToExpiration"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TaxCreditCarryforwardLineItems_1e59c0d2-5437-419d-a074-47051cffef46" xlink:to="loc_us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsNotSubjectToExpiration_48ea88d2-71c7-4537-bef9-62830a425f66" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TaxCreditCarryforwardAmount_69ecda83-8ac2-417a-bfc1-9a8c229f9dd7" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TaxCreditCarryforwardAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TaxCreditCarryforwardLineItems_1e59c0d2-5437-419d-a074-47051cffef46" xlink:to="loc_us-gaap_TaxCreditCarryforwardAmount_69ecda83-8ac2-417a-bfc1-9a8c229f9dd7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_DeferredTaxAssetOperatingLossCarryforwardPeriod_c2026740-639c-4e9f-9d15-21f5d7f60f53" xlink:href="rxt-20201231.xsd#rxt_DeferredTaxAssetOperatingLossCarryforwardPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TaxCreditCarryforwardLineItems_1e59c0d2-5437-419d-a074-47051cffef46" xlink:to="loc_rxt_DeferredTaxAssetOperatingLossCarryforwardPeriod_c2026740-639c-4e9f-9d15-21f5d7f60f53" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetInterestCarryforward_94a076da-c6cf-44d9-9c39-be3f0a52349e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxAssetInterestCarryforward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TaxCreditCarryforwardLineItems_1e59c0d2-5437-419d-a074-47051cffef46" xlink:to="loc_us-gaap_DeferredTaxAssetInterestCarryforward_94a076da-c6cf-44d9-9c39-be3f0a52349e" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_TaxCutsAndJobsActIncompleteAccountingProvisionalIncomeTaxBenefit_baeec3ed-dc45-4644-9b6c-35b9cb74098a" xlink:href="rxt-20201231.xsd#rxt_TaxCutsAndJobsActIncompleteAccountingProvisionalIncomeTaxBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TaxCreditCarryforwardLineItems_1e59c0d2-5437-419d-a074-47051cffef46" xlink:to="loc_rxt_TaxCutsAndJobsActIncompleteAccountingProvisionalIncomeTaxBenefit_baeec3ed-dc45-4644-9b6c-35b9cb74098a" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_TaxCutsAndJobsActFinalIncomeTaxBenefit_710ed20e-0a61-44f8-a90b-45b09d5f00bd" xlink:href="rxt-20201231.xsd#rxt_TaxCutsAndJobsActFinalIncomeTaxBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TaxCreditCarryforwardLineItems_1e59c0d2-5437-419d-a074-47051cffef46" xlink:to="loc_rxt_TaxCutsAndJobsActFinalIncomeTaxBenefit_710ed20e-0a61-44f8-a90b-45b09d5f00bd" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate_fe408d0b-4ff2-45e6-b089-46b664e36e1c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TaxCreditCarryforwardLineItems_1e59c0d2-5437-419d-a074-47051cffef46" xlink:to="loc_us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate_fe408d0b-4ff2-45e6-b089-46b664e36e1c" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExaminationPenaltiesAndInterestAccrued_ba7e13fb-6af4-4734-b05e-39fd5e7bc1ae" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxExaminationPenaltiesAndInterestAccrued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TaxCreditCarryforwardLineItems_1e59c0d2-5437-419d-a074-47051cffef46" xlink:to="loc_us-gaap_IncomeTaxExaminationPenaltiesAndInterestAccrued_ba7e13fb-6af4-4734-b05e-39fd5e7bc1ae" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TaxAdjustmentsSettlementsAndUnusualProvisions_117389e2-da1f-4be4-9857-8db34ff058b7" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TaxAdjustmentsSettlementsAndUnusualProvisions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TaxCreditCarryforwardLineItems_1e59c0d2-5437-419d-a074-47051cffef46" xlink:to="loc_us-gaap_TaxAdjustmentsSettlementsAndUnusualProvisions_117389e2-da1f-4be4-9857-8db34ff058b7" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_IncomeTaxExpenseRemeasurementOfDeferredTaxAssets_a0a6eed2-6b78-4a2c-a9ca-9834d0263567" xlink:href="rxt-20201231.xsd#rxt_IncomeTaxExpenseRemeasurementOfDeferredTaxAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TaxCreditCarryforwardLineItems_1e59c0d2-5437-419d-a074-47051cffef46" xlink:to="loc_rxt_IncomeTaxExpenseRemeasurementOfDeferredTaxAssets_a0a6eed2-6b78-4a2c-a9ca-9834d0263567" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TaxCreditCarryforwardTable_1caec67b-61b8-4191-9ecc-c17b4c9e59a0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TaxCreditCarryforwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_TaxCreditCarryforwardLineItems_1e59c0d2-5437-419d-a074-47051cffef46" xlink:to="loc_us-gaap_TaxCreditCarryforwardTable_1caec67b-61b8-4191-9ecc-c17b4c9e59a0" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityAxis_72435a1e-bdfa-42b5-b0d5-4268edbea479" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxAuthorityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_TaxCreditCarryforwardTable_1caec67b-61b8-4191-9ecc-c17b4c9e59a0" xlink:to="loc_us-gaap_IncomeTaxAuthorityAxis_72435a1e-bdfa-42b5-b0d5-4268edbea479" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_72435a1e-bdfa-42b5-b0d5-4268edbea479_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_72435a1e-bdfa-42b5-b0d5-4268edbea479" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_72435a1e-bdfa-42b5-b0d5-4268edbea479_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_7bff0fb8-988b-4b85-92f2-625e4ca0d6c6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_72435a1e-bdfa-42b5-b0d5-4268edbea479" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_7bff0fb8-988b-4b85-92f2-625e4ca0d6c6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticCountryMember_fe5fe25f-28ce-474a-9164-86b0ac795bad" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DomesticCountryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_7bff0fb8-988b-4b85-92f2-625e4ca0d6c6" xlink:to="loc_us-gaap_DomesticCountryMember_fe5fe25f-28ce-474a-9164-86b0ac795bad" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignCountryMember_7b2268f7-91a0-437a-b6a7-fa34a9b396c1" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ForeignCountryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_7bff0fb8-988b-4b85-92f2-625e4ca0d6c6" xlink:to="loc_us-gaap_ForeignCountryMember_7b2268f7-91a0-437a-b6a7-fa34a9b396c1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_8b3dac50-9cb6-4ef6-b49a-0d09761f764f" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_TaxCreditCarryforwardTable_1caec67b-61b8-4191-9ecc-c17b4c9e59a0" xlink:to="loc_srt_RangeAxis_8b3dac50-9cb6-4ef6-b49a-0d09761f764f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_8b3dac50-9cb6-4ef6-b49a-0d09761f764f_default" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_8b3dac50-9cb6-4ef6-b49a-0d09761f764f" xlink:to="loc_srt_RangeMember_8b3dac50-9cb6-4ef6-b49a-0d09761f764f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_4e6c6187-59bb-4241-9e45-5d2d008d39c6" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_8b3dac50-9cb6-4ef6-b49a-0d09761f764f" xlink:to="loc_srt_RangeMember_4e6c6187-59bb-4241-9e45-5d2d008d39c6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_d204198b-269a-4e10-8205-e739420316a2" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_4e6c6187-59bb-4241-9e45-5d2d008d39c6" xlink:to="loc_srt_MaximumMember_d204198b-269a-4e10-8205-e739420316a2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_d60f3ce6-0a7d-48e5-a0ee-6d79b74e8415" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_4e6c6187-59bb-4241-9e45-5d2d008d39c6" xlink:to="loc_srt_MinimumMember_d60f3ce6-0a7d-48e5-a0ee-6d79b74e8415" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityNameAxis_00554874-7bda-4bf7-840c-54753bc6a1c1" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxAuthorityNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_TaxCreditCarryforwardTable_1caec67b-61b8-4191-9ecc-c17b4c9e59a0" xlink:to="loc_us-gaap_IncomeTaxAuthorityNameAxis_00554874-7bda-4bf7-840c-54753bc6a1c1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityNameDomain_00554874-7bda-4bf7-840c-54753bc6a1c1_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxAuthorityNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeTaxAuthorityNameAxis_00554874-7bda-4bf7-840c-54753bc6a1c1" xlink:to="loc_us-gaap_IncomeTaxAuthorityNameDomain_00554874-7bda-4bf7-840c-54753bc6a1c1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityNameDomain_987cd62e-593f-4f66-9c8c-2501ea803727" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxAuthorityNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeTaxAuthorityNameAxis_00554874-7bda-4bf7-840c-54753bc6a1c1" xlink:to="loc_us-gaap_IncomeTaxAuthorityNameDomain_987cd62e-593f-4f66-9c8c-2501ea803727" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SwissFederalTaxAdministrationFTAMember_7e71ac68-ec8d-4a70-a912-40488e7fc1eb" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SwissFederalTaxAdministrationFTAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityNameDomain_987cd62e-593f-4f66-9c8c-2501ea803727" xlink:to="loc_us-gaap_SwissFederalTaxAdministrationFTAMember_7e71ac68-ec8d-4a70-a912-40488e7fc1eb" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.rackspace.com/role/TaxesStatutoryFederalTaxRateReconciliationDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#TaxesStatutoryFederalTaxRateReconciliationDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/TaxesStatutoryFederalTaxRateReconciliationDetails" xlink:type="extended" id="i0344db2363b14959abe4c205de559587_TaxesStatutoryFederalTaxRateReconciliationDetails"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/TaxesDeferredTaxAssetsandLiabilitiesDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#TaxesDeferredTaxAssetsandLiabilitiesDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/TaxesDeferredTaxAssetsandLiabilitiesDetails" xlink:type="extended" id="i130ad4455b5341a984f035bbb3eed28e_TaxesDeferredTaxAssetsandLiabilitiesDetails"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/TaxesUnrecognizedTaxBenefitsRollforwardDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#TaxesUnrecognizedTaxBenefitsRollforwardDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/TaxesUnrecognizedTaxBenefitsRollforwardDetails" xlink:type="extended" id="i21d2f96f61f844ca88b25e94eb221ad4_TaxesUnrecognizedTaxBenefitsRollforwardDetails"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/Divestitures" xlink:type="simple" xlink:href="rxt-20201231.xsd#Divestitures"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/Divestitures" xlink:type="extended" id="i8bb6559337a24421a3fc1eea923d9343_Divestitures"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/DivestituresNarrativeDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#DivestituresNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/DivestituresNarrativeDetails" xlink:type="extended" id="i5f858d5b6e844157b232d617f55b82aa_DivestituresNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_8847b951-1ea9-456c-9a4e-6ac902d0655e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationConsideration_20a64ead-3f45-4a42-a14d-74d37dee7248" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationConsideration"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_8847b951-1ea9-456c-9a4e-6ac902d0655e" xlink:to="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationConsideration_20a64ead-3f45-4a42-a14d-74d37dee7248" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromDivestitureOfBusinesses_17f87e36-1c9d-44cc-b5f9-3f5211033284" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProceedsFromDivestitureOfBusinesses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_8847b951-1ea9-456c-9a4e-6ac902d0655e" xlink:to="loc_us-gaap_ProceedsFromDivestitureOfBusinesses_17f87e36-1c9d-44cc-b5f9-3f5211033284" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncashOrPartNoncashDivestitureAmountOfConsiderationReceived1_1c5c512d-b473-4e70-bfa0-0a92240a9cc0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NoncashOrPartNoncashDivestitureAmountOfConsiderationReceived1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_8847b951-1ea9-456c-9a4e-6ac902d0655e" xlink:to="loc_us-gaap_NoncashOrPartNoncashDivestitureAmountOfConsiderationReceived1_1c5c512d-b473-4e70-bfa0-0a92240a9cc0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_DisposalGroupIncludingDiscontinuedOperationConsiderationPromissoryNotePaymentPeriod_87ccde17-6077-4994-a81e-8bcc121dff2a" xlink:href="rxt-20201231.xsd#rxt_DisposalGroupIncludingDiscontinuedOperationConsiderationPromissoryNotePaymentPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_8847b951-1ea9-456c-9a4e-6ac902d0655e" xlink:to="loc_rxt_DisposalGroupIncludingDiscontinuedOperationConsiderationPromissoryNotePaymentPeriod_87ccde17-6077-4994-a81e-8bcc121dff2a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_DisposalGroupIncludingDiscontinuedOperationConsiderationPromissoryNoteFairValue_64d9d2ef-9ac7-4db8-850d-bfdd81533967" xlink:href="rxt-20201231.xsd#rxt_DisposalGroupIncludingDiscontinuedOperationConsiderationPromissoryNoteFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_8847b951-1ea9-456c-9a4e-6ac902d0655e" xlink:to="loc_rxt_DisposalGroupIncludingDiscontinuedOperationConsiderationPromissoryNoteFairValue_64d9d2ef-9ac7-4db8-850d-bfdd81533967" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_DisposalGroupIncludingDiscontinuedOperationConsiderationEquityInterestInNewEntity_d2278643-7442-4323-a8cc-66edaa973e24" xlink:href="rxt-20201231.xsd#rxt_DisposalGroupIncludingDiscontinuedOperationConsiderationEquityInterestInNewEntity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_8847b951-1ea9-456c-9a4e-6ac902d0655e" xlink:to="loc_rxt_DisposalGroupIncludingDiscontinuedOperationConsiderationEquityInterestInNewEntity_d2278643-7442-4323-a8cc-66edaa973e24" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnInvestments_d8743ffd-07b2-4f2f-8a9f-e0590442b957" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GainLossOnInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_8847b951-1ea9-456c-9a4e-6ac902d0655e" xlink:to="loc_us-gaap_GainLossOnInvestments_d8743ffd-07b2-4f2f-8a9f-e0590442b957" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_ProceedsFromDivestitureOfBusinessesPromissoryNoteGross_5888b6df-0109-4386-b63b-afd45adb5404" xlink:href="rxt-20201231.xsd#rxt_ProceedsFromDivestitureOfBusinessesPromissoryNoteGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_8847b951-1ea9-456c-9a4e-6ac902d0655e" xlink:to="loc_rxt_ProceedsFromDivestitureOfBusinessesPromissoryNoteGross_5888b6df-0109-4386-b63b-afd45adb5404" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_DisposalGroupIncludingDiscontinuedOperationConsiderationPromissoryNoteOutstanding_9add19c0-4e63-4f09-9b95-8bc42c2dae48" xlink:href="rxt-20201231.xsd#rxt_DisposalGroupIncludingDiscontinuedOperationConsiderationPromissoryNoteOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_8847b951-1ea9-456c-9a4e-6ac902d0655e" xlink:to="loc_rxt_DisposalGroupIncludingDiscontinuedOperationConsiderationPromissoryNoteOutstanding_9add19c0-4e63-4f09-9b95-8bc42c2dae48" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_DisposalGroupIncludingDiscontinuedOperationConsiderationPromissoryNoteInterestPayable_1cf61a55-6985-498d-8eb9-6e0e37734b62" xlink:href="rxt-20201231.xsd#rxt_DisposalGroupIncludingDiscontinuedOperationConsiderationPromissoryNoteInterestPayable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_8847b951-1ea9-456c-9a4e-6ac902d0655e" xlink:to="loc_rxt_DisposalGroupIncludingDiscontinuedOperationConsiderationPromissoryNoteInterestPayable_1cf61a55-6985-498d-8eb9-6e0e37734b62" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnSaleOfBusiness_9a62cac7-eb5c-4f64-81d0-61dd1c95bf63" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GainLossOnSaleOfBusiness"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_8847b951-1ea9-456c-9a4e-6ac902d0655e" xlink:to="loc_us-gaap_GainLossOnSaleOfBusiness_9a62cac7-eb5c-4f64-81d0-61dd1c95bf63" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_DisposalGroupIncludingDiscontinuedOperationsNumberOfDisposals_87a1006a-d476-4ff2-8cd1-6519346b32bc" xlink:href="rxt-20201231.xsd#rxt_DisposalGroupIncludingDiscontinuedOperationsNumberOfDisposals"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_8847b951-1ea9-456c-9a4e-6ac902d0655e" xlink:to="loc_rxt_DisposalGroupIncludingDiscontinuedOperationsNumberOfDisposals_87a1006a-d476-4ff2-8cd1-6519346b32bc" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_735633ef-e2c7-4af7-86e8-688550511c0f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_8847b951-1ea9-456c-9a4e-6ac902d0655e" xlink:to="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_735633ef-e2c7-4af7-86e8-688550511c0f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_87172097-06a7-44f6-93b6-7a6a00964d72" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_735633ef-e2c7-4af7-86e8-688550511c0f" xlink:to="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_87172097-06a7-44f6-93b6-7a6a00964d72" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_87172097-06a7-44f6-93b6-7a6a00964d72_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_87172097-06a7-44f6-93b6-7a6a00964d72" xlink:to="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_87172097-06a7-44f6-93b6-7a6a00964d72_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_1b6fee32-08c7-4b14-9a61-112b9903ef4e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_87172097-06a7-44f6-93b6-7a6a00964d72" xlink:to="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_1b6fee32-08c7-4b14-9a61-112b9903ef4e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_MailgunBusinessMember_80fd6eff-d428-4e5a-86df-fad772d2cc37" xlink:href="rxt-20201231.xsd#rxt_MailgunBusinessMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_1b6fee32-08c7-4b14-9a61-112b9903ef4e" xlink:to="loc_rxt_MailgunBusinessMember_80fd6eff-d428-4e5a-86df-fad772d2cc37" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupClassificationAxis_5d575fb5-d8a0-4310-b393-db1ed9bd9d5f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DisposalGroupClassificationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_735633ef-e2c7-4af7-86e8-688550511c0f" xlink:to="loc_us-gaap_DisposalGroupClassificationAxis_5d575fb5-d8a0-4310-b393-db1ed9bd9d5f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupClassificationDomain_5d575fb5-d8a0-4310-b393-db1ed9bd9d5f_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DisposalGroupClassificationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DisposalGroupClassificationAxis_5d575fb5-d8a0-4310-b393-db1ed9bd9d5f" xlink:to="loc_us-gaap_DisposalGroupClassificationDomain_5d575fb5-d8a0-4310-b393-db1ed9bd9d5f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupClassificationDomain_1fcbb643-09c6-44fc-ab3f-62588923159f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DisposalGroupClassificationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DisposalGroupClassificationAxis_5d575fb5-d8a0-4310-b393-db1ed9bd9d5f" xlink:to="loc_us-gaap_DisposalGroupClassificationDomain_1fcbb643-09c6-44fc-ab3f-62588923159f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember_9db1a09d-3c0b-4a8f-96fe-3e4ec6394143" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisposalGroupClassificationDomain_1fcbb643-09c6-44fc-ab3f-62588923159f" xlink:to="loc_us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember_9db1a09d-3c0b-4a8f-96fe-3e4ec6394143" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_97ba0dbe-f58f-4f45-933a-fc27c015797b" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_735633ef-e2c7-4af7-86e8-688550511c0f" xlink:to="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_97ba0dbe-f58f-4f45-933a-fc27c015797b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_97ba0dbe-f58f-4f45-933a-fc27c015797b_default" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_97ba0dbe-f58f-4f45-933a-fc27c015797b" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_97ba0dbe-f58f-4f45-933a-fc27c015797b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_2023f9a5-4354-4f8b-965f-743f159691c9" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_97ba0dbe-f58f-4f45-933a-fc27c015797b" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_2023f9a5-4354-4f8b-965f-743f159691c9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_MailgunTechnologiesMember_be1f9d0e-b0ad-4ac7-9d54-77f5101b0ce0" xlink:href="rxt-20201231.xsd#rxt_MailgunTechnologiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_2023f9a5-4354-4f8b-965f-743f159691c9" xlink:to="loc_rxt_MailgunTechnologiesMember_be1f9d0e-b0ad-4ac7-9d54-77f5101b0ce0" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.rackspace.com/role/Acquisitions" xlink:type="simple" xlink:href="rxt-20201231.xsd#Acquisitions"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/Acquisitions" xlink:type="extended" id="ie9050596a1a64dcea1593d8d3115e7a3_Acquisitions"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/AcquisitionsTables" xlink:type="simple" xlink:href="rxt-20201231.xsd#AcquisitionsTables"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/AcquisitionsTables" xlink:type="extended" id="ic55801ff567f4adeb6d276375f516cf8_AcquisitionsTables">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_505c70cb-61d7-47b1-82fe-61176a43540c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock_04c59d75-93bc-4156-b05a-7d4dc7abd30c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_505c70cb-61d7-47b1-82fe-61176a43540c" xlink:to="loc_us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock_04c59d75-93bc-4156-b05a-7d4dc7abd30c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionProFormaInformationTextBlock_83707ef6-1b33-4a84-87bc-3fb9d50ba7c5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionProFormaInformationTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_505c70cb-61d7-47b1-82fe-61176a43540c" xlink:to="loc_us-gaap_BusinessAcquisitionProFormaInformationTextBlock_83707ef6-1b33-4a84-87bc-3fb9d50ba7c5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTextBlock_5d6b44b4-d2e5-4ad4-a3b7-479cfb82af0b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_505c70cb-61d7-47b1-82fe-61176a43540c" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTextBlock_5d6b44b4-d2e5-4ad4-a3b7-479cfb82af0b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_a9d9bf1d-886e-40c0-acbc-96354cbc95bd" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_505c70cb-61d7-47b1-82fe-61176a43540c" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_a9d9bf1d-886e-40c0-acbc-96354cbc95bd" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_f1c92a3f-8f35-4547-9030-9b496584730a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_a9d9bf1d-886e-40c0-acbc-96354cbc95bd" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_f1c92a3f-8f35-4547-9030-9b496584730a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_f1c92a3f-8f35-4547-9030-9b496584730a_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_f1c92a3f-8f35-4547-9030-9b496584730a" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_f1c92a3f-8f35-4547-9030-9b496584730a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_14bb52c9-b6e2-4095-a29d-abbe5d89c1fd" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_f1c92a3f-8f35-4547-9030-9b496584730a" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_14bb52c9-b6e2-4095-a29d-abbe5d89c1fd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_RelationEdgeLLCMember_31545403-a19f-4a88-ad29-e60407e6cf2b" xlink:href="rxt-20201231.xsd#rxt_RelationEdgeLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_14bb52c9-b6e2-4095-a29d-abbe5d89c1fd" xlink:to="loc_rxt_RelationEdgeLLCMember_31545403-a19f-4a88-ad29-e60407e6cf2b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_OnicaHoldingsLLCMember_a76451fc-fb5c-4a2c-88fc-f2fcc503cdf8" xlink:href="rxt-20201231.xsd#rxt_OnicaHoldingsLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_14bb52c9-b6e2-4095-a29d-abbe5d89c1fd" xlink:to="loc_rxt_OnicaHoldingsLLCMember_a76451fc-fb5c-4a2c-88fc-f2fcc503cdf8" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.rackspace.com/role/AcquisitionsNarrativeDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#AcquisitionsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/AcquisitionsNarrativeDetails" xlink:type="extended" id="i7de8a239ef024bf8a282269ded267efa_AcquisitionsNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_4ac0cb9e-13a3-4ab3-bf73-17a530592f30" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_46aa2540-0a73-4d6c-abbf-fcacb4fa6b0b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4ac0cb9e-13a3-4ab3-bf73-17a530592f30" xlink:to="loc_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_46aa2540-0a73-4d6c-abbf-fcacb4fa6b0b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesGross_cc5cd966-57ff-4d4d-a90a-37f3ada0ffcf" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsToAcquireBusinessesGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4ac0cb9e-13a3-4ab3-bf73-17a530592f30" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesGross_cc5cd966-57ff-4d4d-a90a-37f3ada0ffcf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAcquiredFromAcquisition_37aaa23a-9b27-453e-b8e5-f660780fd3af" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CashAcquiredFromAcquisition"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4ac0cb9e-13a3-4ab3-bf73-17a530592f30" xlink:to="loc_us-gaap_CashAcquiredFromAcquisition_37aaa23a-9b27-453e-b8e5-f660780fd3af" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_68da0173-26ff-4fa7-a0c6-b8c13e3edb10" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4ac0cb9e-13a3-4ab3-bf73-17a530592f30" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_68da0173-26ff-4fa7-a0c6-b8c13e3edb10" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill_4932df43-cf4f-4204-9872-673a79ee3f93" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4ac0cb9e-13a3-4ab3-bf73-17a530592f30" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill_4932df43-cf4f-4204-9872-673a79ee3f93" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_16f38ab1-f472-4018-94aa-0dd249fa3279" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4ac0cb9e-13a3-4ab3-bf73-17a530592f30" xlink:to="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_16f38ab1-f472-4018-94aa-0dd249fa3279" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_abd52876-bacc-4cac-aef2-ff36b0abe64b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationAcquisitionRelatedCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4ac0cb9e-13a3-4ab3-bf73-17a530592f30" xlink:to="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_abd52876-bacc-4cac-aef2-ff36b0abe64b" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductibleAmount_c61a9355-15fb-4d96-a810-6878d9effbc8" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductibleAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4ac0cb9e-13a3-4ab3-bf73-17a530592f30" xlink:to="loc_us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductibleAmount_c61a9355-15fb-4d96-a810-6878d9effbc8" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentConsiderationTransferred_0b60a81e-a910-4630-a54f-7b422ac9c368" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentConsiderationTransferred"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4ac0cb9e-13a3-4ab3-bf73-17a530592f30" xlink:to="loc_us-gaap_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentConsiderationTransferred_0b60a81e-a910-4630-a54f-7b422ac9c368" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentDeferredTaxes_41224999-3671-4ca8-973f-d36c7804b93d" xlink:href="rxt-20201231.xsd#rxt_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentDeferredTaxes"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4ac0cb9e-13a3-4ab3-bf73-17a530592f30" xlink:to="loc_rxt_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentDeferredTaxes_41224999-3671-4ca8-973f-d36c7804b93d" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillPurchaseAccountingAdjustments_3a100334-c06b-4b78-b61e-830ac91d2a03" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GoodwillPurchaseAccountingAdjustments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4ac0cb9e-13a3-4ab3-bf73-17a530592f30" xlink:to="loc_us-gaap_GoodwillPurchaseAccountingAdjustments_3a100334-c06b-4b78-b61e-830ac91d2a03" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_efce25f6-b444-4554-88f1-f7a7ce41b982" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4ac0cb9e-13a3-4ab3-bf73-17a530592f30" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_efce25f6-b444-4554-88f1-f7a7ce41b982" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_8e9fc130-64a5-4ee9-a89d-155190128cf6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_efce25f6-b444-4554-88f1-f7a7ce41b982" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_8e9fc130-64a5-4ee9-a89d-155190128cf6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_8e9fc130-64a5-4ee9-a89d-155190128cf6_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_8e9fc130-64a5-4ee9-a89d-155190128cf6" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_8e9fc130-64a5-4ee9-a89d-155190128cf6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_bdac13d3-1134-4ab9-89e0-8229e4d26ae6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_8e9fc130-64a5-4ee9-a89d-155190128cf6" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_bdac13d3-1134-4ab9-89e0-8229e4d26ae6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_RelationshipWithSalesforceMember_af69fea8-6c9b-4312-add9-db5b9d360a42" xlink:href="rxt-20201231.xsd#rxt_RelationshipWithSalesforceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_bdac13d3-1134-4ab9-89e0-8229e4d26ae6" xlink:to="loc_rxt_RelationshipWithSalesforceMember_af69fea8-6c9b-4312-add9-db5b9d360a42" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelationshipsMember_41ec3ca4-9cf3-4dfd-b417-6c781269c697" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CustomerRelationshipsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_bdac13d3-1134-4ab9-89e0-8229e4d26ae6" xlink:to="loc_us-gaap_CustomerRelationshipsMember_41ec3ca4-9cf3-4dfd-b417-6c781269c697" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_RelationshipWithAWSMember_90fb5396-46af-4095-beb9-048b972a44da" xlink:href="rxt-20201231.xsd#rxt_RelationshipWithAWSMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_bdac13d3-1134-4ab9-89e0-8229e4d26ae6" xlink:to="loc_rxt_RelationshipWithAWSMember_90fb5396-46af-4095-beb9-048b972a44da" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_b0443d04-4944-42b8-b3a7-9d7cf73f4617" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_efce25f6-b444-4554-88f1-f7a7ce41b982" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_b0443d04-4944-42b8-b3a7-9d7cf73f4617" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_b0443d04-4944-42b8-b3a7-9d7cf73f4617_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_b0443d04-4944-42b8-b3a7-9d7cf73f4617" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_b0443d04-4944-42b8-b3a7-9d7cf73f4617_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_abbd89d7-9294-4940-8dc7-b14dd8974ca4" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_b0443d04-4944-42b8-b3a7-9d7cf73f4617" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_abbd89d7-9294-4940-8dc7-b14dd8974ca4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_RelationEdgeLLCMember_128fc4e6-5a65-42d2-8c8f-826fec621292" xlink:href="rxt-20201231.xsd#rxt_RelationEdgeLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_abbd89d7-9294-4940-8dc7-b14dd8974ca4" xlink:to="loc_rxt_RelationEdgeLLCMember_128fc4e6-5a65-42d2-8c8f-826fec621292" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_OnicaHoldingsLLCMember_ded75a91-1f29-41b8-b631-85d3fa38965e" xlink:href="rxt-20201231.xsd#rxt_OnicaHoldingsLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_abbd89d7-9294-4940-8dc7-b14dd8974ca4" xlink:to="loc_rxt_OnicaHoldingsLLCMember_ded75a91-1f29-41b8-b631-85d3fa38965e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_BrightSkiesMember_559442fa-d8cd-4311-a11d-05ccf49750fd" xlink:href="rxt-20201231.xsd#rxt_BrightSkiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_abbd89d7-9294-4940-8dc7-b14dd8974ca4" xlink:to="loc_rxt_BrightSkiesMember_559442fa-d8cd-4311-a11d-05ccf49750fd" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_e4e78815-c080-45e5-82b1-b3b28c2bad6a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeStatementLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_efce25f6-b444-4554-88f1-f7a7ce41b982" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_e4e78815-c080-45e5-82b1-b3b28c2bad6a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_e4e78815-c080-45e5-82b1-b3b28c2bad6a_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_e4e78815-c080-45e5-82b1-b3b28c2bad6a" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_e4e78815-c080-45e5-82b1-b3b28c2bad6a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_79ec1244-824c-4be7-bb38-48c34cb9398d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_e4e78815-c080-45e5-82b1-b3b28c2bad6a" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_79ec1244-824c-4be7-bb38-48c34cb9398d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpensesMember_7808f33b-b13c-4531-a334-8012664f1a50" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SellingGeneralAndAdministrativeExpensesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_79ec1244-824c-4be7-bb38-48c34cb9398d" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpensesMember_7808f33b-b13c-4531-a334-8012664f1a50" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.rackspace.com/role/AcquisitionsScheduleofPreliminaryPurchasePriceAllocationDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#AcquisitionsScheduleofPreliminaryPurchasePriceAllocationDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/AcquisitionsScheduleofPreliminaryPurchasePriceAllocationDetails" xlink:type="extended" id="iad7add4dc5d640d4a1ffaacebdea9810_AcquisitionsScheduleofPreliminaryPurchasePriceAllocationDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_dec70370-5f02-4d16-aafc-278e6896877e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_24cb6a0c-68b9-416a-9937-9eb627976ad8" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_dec70370-5f02-4d16-aafc-278e6896877e" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_24cb6a0c-68b9-416a-9937-9eb627976ad8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents_2a459bc2-8931-47f9-9486-626263e08856" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_dec70370-5f02-4d16-aafc-278e6896877e" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents_2a459bc2-8931-47f9-9486-626263e08856" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill_1d540148-aa79-4718-b30c-4b34d5ac4cea" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_dec70370-5f02-4d16-aafc-278e6896877e" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill_1d540148-aa79-4718-b30c-4b34d5ac4cea" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAssumedNetOfOtherAssetsAcquired_3d65907f-9115-4cd5-a85b-f6a18e46ff0c" xlink:href="rxt-20201231.xsd#rxt_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAssumedNetOfOtherAssetsAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_dec70370-5f02-4d16-aafc-278e6896877e" xlink:to="loc_rxt_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAssumedNetOfOtherAssetsAcquired_3d65907f-9115-4cd5-a85b-f6a18e46ff0c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet_26da4497-45db-4207-8faa-d1373e69a710" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_dec70370-5f02-4d16-aafc-278e6896877e" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet_26da4497-45db-4207-8faa-d1373e69a710" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_812449d8-fb70-409a-be7a-72de7841163b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_dec70370-5f02-4d16-aafc-278e6896877e" xlink:to="loc_us-gaap_Goodwill_812449d8-fb70-409a-be7a-72de7841163b" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_38c9ddc1-db1a-4f92-b22e-4af14f1fce6d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_dec70370-5f02-4d16-aafc-278e6896877e" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_38c9ddc1-db1a-4f92-b22e-4af14f1fce6d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_5a4bec5e-23a7-4d95-af24-f8370acd55b8" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_38c9ddc1-db1a-4f92-b22e-4af14f1fce6d" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_5a4bec5e-23a7-4d95-af24-f8370acd55b8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_5a4bec5e-23a7-4d95-af24-f8370acd55b8_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_5a4bec5e-23a7-4d95-af24-f8370acd55b8" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_5a4bec5e-23a7-4d95-af24-f8370acd55b8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_fd634004-9a2d-427e-bb39-60bd782c77db" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_5a4bec5e-23a7-4d95-af24-f8370acd55b8" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_fd634004-9a2d-427e-bb39-60bd782c77db" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_RelationEdgeLLCMember_5e511011-9901-4888-9565-de4654fd3ce7" xlink:href="rxt-20201231.xsd#rxt_RelationEdgeLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_fd634004-9a2d-427e-bb39-60bd782c77db" xlink:to="loc_rxt_RelationEdgeLLCMember_5e511011-9901-4888-9565-de4654fd3ce7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_OnicaHoldingsLLCMember_0ee02e4c-84d5-45ea-b2e8-2038915aa32b" xlink:href="rxt-20201231.xsd#rxt_OnicaHoldingsLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_fd634004-9a2d-427e-bb39-60bd782c77db" xlink:to="loc_rxt_OnicaHoldingsLLCMember_0ee02e4c-84d5-45ea-b2e8-2038915aa32b" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.rackspace.com/role/AcquisitionsProFormaSummaryDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#AcquisitionsProFormaSummaryDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/AcquisitionsProFormaSummaryDetails" xlink:type="extended" id="if65b33503d4c4ba7865ce6c61d91eb7b_AcquisitionsProFormaSummaryDetails"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/AcquisitionsScheduleofAdjustmentstothePreliminaryAllocationDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#AcquisitionsScheduleofAdjustmentstothePreliminaryAllocationDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/AcquisitionsScheduleofAdjustmentstothePreliminaryAllocationDetails" xlink:type="extended" id="icc380f1c7df8481093356c5a447c0bc5_AcquisitionsScheduleofAdjustmentstothePreliminaryAllocationDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_8e1cc471-bb27-467d-a869-b0fef5140cf4" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_4fb6d106-8b57-4109-8942-c469492333aa" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_8e1cc471-bb27-467d-a869-b0fef5140cf4" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_4fb6d106-8b57-4109-8942-c469492333aa" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentConsiderationTransferred_a4b0c84c-a78b-4038-bafa-1456eef5298c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentConsiderationTransferred"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_8e1cc471-bb27-467d-a869-b0fef5140cf4" xlink:to="loc_us-gaap_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentConsiderationTransferred_a4b0c84c-a78b-4038-bafa-1456eef5298c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAssumedNetOfOtherAssetsAcquired_b95f6703-066b-490a-b08a-2c039d079604" xlink:href="rxt-20201231.xsd#rxt_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAssumedNetOfOtherAssetsAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_8e1cc471-bb27-467d-a869-b0fef5140cf4" xlink:to="loc_rxt_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAssumedNetOfOtherAssetsAcquired_b95f6703-066b-490a-b08a-2c039d079604" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentDeferredTaxes_7a33e624-fe2c-4c6d-88da-cf317dccef7a" xlink:href="rxt-20201231.xsd#rxt_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentDeferredTaxes"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_8e1cc471-bb27-467d-a869-b0fef5140cf4" xlink:to="loc_rxt_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentDeferredTaxes_7a33e624-fe2c-4c6d-88da-cf317dccef7a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_cd787459-42ab-4a1b-86fd-57166912a6ee" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_8e1cc471-bb27-467d-a869-b0fef5140cf4" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_cd787459-42ab-4a1b-86fd-57166912a6ee" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_9392ae56-6206-4665-9d37-4b9277b1433a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_cd787459-42ab-4a1b-86fd-57166912a6ee" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_9392ae56-6206-4665-9d37-4b9277b1433a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_9392ae56-6206-4665-9d37-4b9277b1433a_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_9392ae56-6206-4665-9d37-4b9277b1433a" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_9392ae56-6206-4665-9d37-4b9277b1433a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_0d39a50a-747a-4326-9af8-6fe581bad6b7" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_9392ae56-6206-4665-9d37-4b9277b1433a" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_0d39a50a-747a-4326-9af8-6fe581bad6b7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_OnicaHoldingsLLCMember_b4019780-ebf1-45f4-89b5-3e0596b6ad10" xlink:href="rxt-20201231.xsd#rxt_OnicaHoldingsLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_0d39a50a-747a-4326-9af8-6fe581bad6b7" xlink:to="loc_rxt_OnicaHoldingsLLCMember_b4019780-ebf1-45f4-89b5-3e0596b6ad10" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.rackspace.com/role/Derivatives" xlink:type="simple" xlink:href="rxt-20201231.xsd#Derivatives"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/Derivatives" xlink:type="extended" id="i24a57516008648c4baa78c2fe3c1d26e_Derivatives"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/DerivativesTables" xlink:type="simple" xlink:href="rxt-20201231.xsd#DerivativesTables"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/DerivativesTables" xlink:type="extended" id="id2bde769013f44598baa8ca69829c8c4_DerivativesTables"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/DerivativesNarrativeDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#DerivativesNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/DerivativesNarrativeDetails" xlink:type="extended" id="i5ed56f4bca674a6593d47e73d2652618_DerivativesNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLineItems_8be18cf2-9f41-4a18-a47f-6b6f4e8be6a4" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeNumberOfInstrumentsHeld_71e870db-a633-4422-b65c-f8ec1030b54f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeNumberOfInstrumentsHeld"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_8be18cf2-9f41-4a18-a47f-6b6f4e8be6a4" xlink:to="loc_us-gaap_DerivativeNumberOfInstrumentsHeld_71e870db-a633-4422-b65c-f8ec1030b54f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeNotionalAmount_d22c624d-2ba7-4f8b-810c-a5c4f26335e2" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeNotionalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_8be18cf2-9f41-4a18-a47f-6b6f4e8be6a4" xlink:to="loc_us-gaap_DerivativeNotionalAmount_d22c624d-2ba7-4f8b-810c-a5c4f26335e2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_DerivativeNumberOfInstrumentsMaturedDuringPeriod_f7773aca-154d-4b02-9d2b-dd8e85c42f9b" xlink:href="rxt-20201231.xsd#rxt_DerivativeNumberOfInstrumentsMaturedDuringPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_8be18cf2-9f41-4a18-a47f-6b6f4e8be6a4" xlink:to="loc_rxt_DerivativeNumberOfInstrumentsMaturedDuringPeriod_f7773aca-154d-4b02-9d2b-dd8e85c42f9b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeRemainingMaturity1_c44947e4-f0e6-4cb6-ae0a-77278fcb677e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeRemainingMaturity1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_8be18cf2-9f41-4a18-a47f-6b6f4e8be6a4" xlink:to="loc_us-gaap_DerivativeRemainingMaturity1_c44947e4-f0e6-4cb6-ae0a-77278fcb677e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_DerivativeNumberOfInstrumentsHeldDeemedEffective_434442e7-0fcd-4527-9d11-5bca3f7e3924" xlink:href="rxt-20201231.xsd#rxt_DerivativeNumberOfInstrumentsHeldDeemedEffective"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_8be18cf2-9f41-4a18-a47f-6b6f4e8be6a4" xlink:to="loc_rxt_DerivativeNumberOfInstrumentsHeldDeemedEffective_434442e7-0fcd-4527-9d11-5bca3f7e3924" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_DerivativeNotionalAmountDeemedEffective_cdd60e19-c0d9-45e6-971c-f8e311472449" xlink:href="rxt-20201231.xsd#rxt_DerivativeNotionalAmountDeemedEffective"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_8be18cf2-9f41-4a18-a47f-6b6f4e8be6a4" xlink:to="loc_rxt_DerivativeNotionalAmountDeemedEffective_cdd60e19-c0d9-45e6-971c-f8e311472449" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeFixedInterestRate_1b7d1da0-c6f0-41e6-a0e5-8d3691a03a25" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeFixedInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_8be18cf2-9f41-4a18-a47f-6b6f4e8be6a4" xlink:to="loc_us-gaap_DerivativeFixedInterestRate_1b7d1da0-c6f0-41e6-a0e5-8d3691a03a25" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeForwardExchangeRate1_aa1f975a-748e-447b-814f-156fd79dcb3a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeForwardExchangeRate1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_8be18cf2-9f41-4a18-a47f-6b6f4e8be6a4" xlink:to="loc_us-gaap_DerivativeForwardExchangeRate1_aa1f975a-748e-447b-814f-156fd79dcb3a" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_DerivativeNetPaymentProceedsAfterSettlement_87209585-39c2-41fe-9c63-126609f5e880" xlink:href="rxt-20201231.xsd#rxt_DerivativeNetPaymentProceedsAfterSettlement"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_8be18cf2-9f41-4a18-a47f-6b6f4e8be6a4" xlink:to="loc_rxt_DerivativeNetPaymentProceedsAfterSettlement_87209585-39c2-41fe-9c63-126609f5e880" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_DerivativeNumberOfInstrumentsSettled_dfb8d826-d934-43be-975f-7a02f4d3b70a" xlink:href="rxt-20201231.xsd#rxt_DerivativeNumberOfInstrumentsSettled"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_8be18cf2-9f41-4a18-a47f-6b6f4e8be6a4" xlink:to="loc_rxt_DerivativeNumberOfInstrumentsSettled_dfb8d826-d934-43be-975f-7a02f4d3b70a" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_DerivativeNotionalAmountSettled_308edba4-04ae-4192-8f7f-e1b6f544a500" xlink:href="rxt-20201231.xsd#rxt_DerivativeNotionalAmountSettled"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_8be18cf2-9f41-4a18-a47f-6b6f4e8be6a4" xlink:to="loc_rxt_DerivativeNotionalAmountSettled_308edba4-04ae-4192-8f7f-e1b6f544a500" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeTermOfContract_6720892d-6c11-4013-b3fa-710dce9826c9" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeTermOfContract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_8be18cf2-9f41-4a18-a47f-6b6f4e8be6a4" xlink:to="loc_us-gaap_DerivativeTermOfContract_6720892d-6c11-4013-b3fa-710dce9826c9" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpense_5a5b5cf4-2b1f-4810-8f81-f56813b9415a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InterestExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_8be18cf2-9f41-4a18-a47f-6b6f4e8be6a4" xlink:to="loc_us-gaap_InterestExpense_5a5b5cf4-2b1f-4810-8f81-f56813b9415a" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashFlowHedgeGainLossToBeReclassifiedWithinTwelveMonths_4ccb10ca-b5bb-4417-ba6b-59617015d19b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CashFlowHedgeGainLossToBeReclassifiedWithinTwelveMonths"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_8be18cf2-9f41-4a18-a47f-6b6f4e8be6a4" xlink:to="loc_us-gaap_CashFlowHedgeGainLossToBeReclassifiedWithinTwelveMonths_4ccb10ca-b5bb-4417-ba6b-59617015d19b" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilities_5b12733a-8c3f-43df-a8d8-b79908fad74d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_8be18cf2-9f41-4a18-a47f-6b6f4e8be6a4" xlink:to="loc_us-gaap_DerivativeLiabilities_5b12733a-8c3f-43df-a8d8-b79908fad74d" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeTable_3b2aeddd-a153-4a18-a8bf-4c76123ad630" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeLineItems_8be18cf2-9f41-4a18-a47f-6b6f4e8be6a4" xlink:to="loc_us-gaap_DerivativeTable_3b2aeddd-a153-4a18-a8bf-4c76123ad630" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_d081c2e0-69c8-4c9d-a3c4-b72e3275448b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_3b2aeddd-a153-4a18-a8bf-4c76123ad630" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_d081c2e0-69c8-4c9d-a3c4-b72e3275448b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_d081c2e0-69c8-4c9d-a3c4-b72e3275448b_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_d081c2e0-69c8-4c9d-a3c4-b72e3275448b" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_d081c2e0-69c8-4c9d-a3c4-b72e3275448b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_75d7ef6d-d9cd-4a2b-b269-4e35f6a46071" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_d081c2e0-69c8-4c9d-a3c4-b72e3275448b" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_75d7ef6d-d9cd-4a2b-b269-4e35f6a46071" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateSwapMember_3ab788c1-c036-40c8-af83-3d58cae5b196" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InterestRateSwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_75d7ef6d-d9cd-4a2b-b269-4e35f6a46071" xlink:to="loc_us-gaap_InterestRateSwapMember_3ab788c1-c036-40c8-af83-3d58cae5b196" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_InterestRateSwapOneMember_ba6f09c2-5624-4095-8cb4-fc0a5d0da973" xlink:href="rxt-20201231.xsd#rxt_InterestRateSwapOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InterestRateSwapMember_3ab788c1-c036-40c8-af83-3d58cae5b196" xlink:to="loc_rxt_InterestRateSwapOneMember_ba6f09c2-5624-4095-8cb4-fc0a5d0da973" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_InterestRateSwapTwoMember_e26bb272-f676-4547-bb45-0f3ddce3f48f" xlink:href="rxt-20201231.xsd#rxt_InterestRateSwapTwoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InterestRateSwapMember_3ab788c1-c036-40c8-af83-3d58cae5b196" xlink:to="loc_rxt_InterestRateSwapTwoMember_e26bb272-f676-4547-bb45-0f3ddce3f48f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_ForeignExchangeForwardSixMember_72a14f50-22d4-43f1-a309-69460800dfde" xlink:href="rxt-20201231.xsd#rxt_ForeignExchangeForwardSixMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_75d7ef6d-d9cd-4a2b-b269-4e35f6a46071" xlink:to="loc_rxt_ForeignExchangeForwardSixMember_72a14f50-22d4-43f1-a309-69460800dfde" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_ForeignExchangeForwardOneMember_36a493bd-d36e-432f-b9ba-2c9d72c3214e" xlink:href="rxt-20201231.xsd#rxt_ForeignExchangeForwardOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_75d7ef6d-d9cd-4a2b-b269-4e35f6a46071" xlink:to="loc_rxt_ForeignExchangeForwardOneMember_36a493bd-d36e-432f-b9ba-2c9d72c3214e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_ForeignExchangeForwardTwoMember_04eacb72-46b0-4f63-a30f-5f95151f947e" xlink:href="rxt-20201231.xsd#rxt_ForeignExchangeForwardTwoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_75d7ef6d-d9cd-4a2b-b269-4e35f6a46071" xlink:to="loc_rxt_ForeignExchangeForwardTwoMember_04eacb72-46b0-4f63-a30f-5f95151f947e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_ForeignExchangeForwardThreeMember_206f3d18-1c33-4344-8b87-90f0f5c4fec9" xlink:href="rxt-20201231.xsd#rxt_ForeignExchangeForwardThreeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_75d7ef6d-d9cd-4a2b-b269-4e35f6a46071" xlink:to="loc_rxt_ForeignExchangeForwardThreeMember_206f3d18-1c33-4344-8b87-90f0f5c4fec9" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_ForeignExchangeForwardFourMember_7a8b9f3a-1a36-43b9-ade4-dd44e356fdc2" xlink:href="rxt-20201231.xsd#rxt_ForeignExchangeForwardFourMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_75d7ef6d-d9cd-4a2b-b269-4e35f6a46071" xlink:to="loc_rxt_ForeignExchangeForwardFourMember_7a8b9f3a-1a36-43b9-ade4-dd44e356fdc2" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_6452b251-8836-41f7-b33e-f124614260f1" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_3b2aeddd-a153-4a18-a8bf-4c76123ad630" xlink:to="loc_srt_RangeAxis_6452b251-8836-41f7-b33e-f124614260f1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_6452b251-8836-41f7-b33e-f124614260f1_default" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_6452b251-8836-41f7-b33e-f124614260f1" xlink:to="loc_srt_RangeMember_6452b251-8836-41f7-b33e-f124614260f1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_dd3eb6da-6a0a-42c5-a733-d40cae6710ea" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_6452b251-8836-41f7-b33e-f124614260f1" xlink:to="loc_srt_RangeMember_dd3eb6da-6a0a-42c5-a733-d40cae6710ea" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_4f19b49b-725a-42d6-93fe-24f8295727be" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_dd3eb6da-6a0a-42c5-a733-d40cae6710ea" xlink:to="loc_srt_MinimumMember_4f19b49b-725a-42d6-93fe-24f8295727be" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_947d78c7-f721-4105-a248-f48e35cdccd1" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_dd3eb6da-6a0a-42c5-a733-d40cae6710ea" xlink:to="loc_srt_MaximumMember_947d78c7-f721-4105-a248-f48e35cdccd1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationAxis_9082d03b-6829-45f0-b579-4819f56563c2" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_HedgingDesignationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_3b2aeddd-a153-4a18-a8bf-4c76123ad630" xlink:to="loc_us-gaap_HedgingDesignationAxis_9082d03b-6829-45f0-b579-4819f56563c2" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_9082d03b-6829-45f0-b579-4819f56563c2_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_9082d03b-6829-45f0-b579-4819f56563c2" xlink:to="loc_us-gaap_HedgingDesignationDomain_9082d03b-6829-45f0-b579-4819f56563c2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_cf5e14df-0c2c-4cbc-881f-b695e8a591a1" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_9082d03b-6829-45f0-b579-4819f56563c2" xlink:to="loc_us-gaap_HedgingDesignationDomain_cf5e14df-0c2c-4cbc-881f-b695e8a591a1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DesignatedAsHedgingInstrumentMember_de0d62cf-9587-438b-8fad-9fbaa835b267" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DesignatedAsHedgingInstrumentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_cf5e14df-0c2c-4cbc-881f-b695e8a591a1" xlink:to="loc_us-gaap_DesignatedAsHedgingInstrumentMember_de0d62cf-9587-438b-8fad-9fbaa835b267" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.rackspace.com/role/DerivativesScheduleofFairValuesofDerivativesontheConsolidatedBalanceSheetsDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#DerivativesScheduleofFairValuesofDerivativesontheConsolidatedBalanceSheetsDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/DerivativesScheduleofFairValuesofDerivativesontheConsolidatedBalanceSheetsDetails" xlink:type="extended" id="i2e33c904b80e40eaa25c79e1ee7f4fe4_DerivativesScheduleofFairValuesofDerivativesontheConsolidatedBalanceSheetsDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativesFairValueLineItems_c758b1e5-7693-443b-9358-9345ce895fad" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativesFairValueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssets_414eaa6d-a88e-4cd9-9480-d01e5c875b6e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_c758b1e5-7693-443b-9358-9345ce895fad" xlink:to="loc_us-gaap_DerivativeAssets_414eaa6d-a88e-4cd9-9480-d01e5c875b6e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilities_f436ffd6-e149-4c21-a684-8a5cb2b4ae32" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_c758b1e5-7693-443b-9358-9345ce895fad" xlink:to="loc_us-gaap_DerivativeLiabilities_f436ffd6-e149-4c21-a684-8a5cb2b4ae32" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_e9eea47d-4df0-458a-960b-e5e3d4dbacea" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_c758b1e5-7693-443b-9358-9345ce895fad" xlink:to="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_e9eea47d-4df0-458a-960b-e5e3d4dbacea" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationAxis_0e3ad17e-cccb-423a-aeae-ea2fb513152b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_HedgingDesignationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_e9eea47d-4df0-458a-960b-e5e3d4dbacea" xlink:to="loc_us-gaap_HedgingDesignationAxis_0e3ad17e-cccb-423a-aeae-ea2fb513152b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_0e3ad17e-cccb-423a-aeae-ea2fb513152b_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_0e3ad17e-cccb-423a-aeae-ea2fb513152b" xlink:to="loc_us-gaap_HedgingDesignationDomain_0e3ad17e-cccb-423a-aeae-ea2fb513152b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_3cdef9b0-4140-4e86-84e1-8df86506296c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_0e3ad17e-cccb-423a-aeae-ea2fb513152b" xlink:to="loc_us-gaap_HedgingDesignationDomain_3cdef9b0-4140-4e86-84e1-8df86506296c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NondesignatedMember_42950888-5286-4d37-a567-d2a62c36f31a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NondesignatedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_3cdef9b0-4140-4e86-84e1-8df86506296c" xlink:to="loc_us-gaap_NondesignatedMember_42950888-5286-4d37-a567-d2a62c36f31a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DesignatedAsHedgingInstrumentMember_7f5caa4f-c614-40e7-a5be-ca5344e0b8b4" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DesignatedAsHedgingInstrumentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_3cdef9b0-4140-4e86-84e1-8df86506296c" xlink:to="loc_us-gaap_DesignatedAsHedgingInstrumentMember_7f5caa4f-c614-40e7-a5be-ca5344e0b8b4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationAxis_184bd994-c3d4-4578-8e01-82923e6dc03b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BalanceSheetLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_e9eea47d-4df0-458a-960b-e5e3d4dbacea" xlink:to="loc_us-gaap_BalanceSheetLocationAxis_184bd994-c3d4-4578-8e01-82923e6dc03b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_184bd994-c3d4-4578-8e01-82923e6dc03b_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BalanceSheetLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_184bd994-c3d4-4578-8e01-82923e6dc03b" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_184bd994-c3d4-4578-8e01-82923e6dc03b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_fa6786a7-4e14-4169-9838-c9e2c29f60b1" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BalanceSheetLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_184bd994-c3d4-4578-8e01-82923e6dc03b" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_fa6786a7-4e14-4169-9838-c9e2c29f60b1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCurrentLiabilitiesMember_e3a30d37-e963-406c-a8ba-6b8b86dc2562" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherCurrentLiabilitiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_fa6786a7-4e14-4169-9838-c9e2c29f60b1" xlink:to="loc_us-gaap_OtherCurrentLiabilitiesMember_e3a30d37-e963-406c-a8ba-6b8b86dc2562" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNoncurrentLiabilitiesMember_181108fc-a826-4e70-af85-fb321a53a1ff" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherNoncurrentLiabilitiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_fa6786a7-4e14-4169-9838-c9e2c29f60b1" xlink:to="loc_us-gaap_OtherNoncurrentLiabilitiesMember_181108fc-a826-4e70-af85-fb321a53a1ff" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCurrentAssetsMember_bd0d4a0f-7c1f-4727-ac75-d7c93f77eb4b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherCurrentAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_fa6786a7-4e14-4169-9838-c9e2c29f60b1" xlink:to="loc_us-gaap_OtherCurrentAssetsMember_bd0d4a0f-7c1f-4727-ac75-d7c93f77eb4b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_8d596018-7ae8-4706-9211-25682a5ba65a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_e9eea47d-4df0-458a-960b-e5e3d4dbacea" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_8d596018-7ae8-4706-9211-25682a5ba65a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_8d596018-7ae8-4706-9211-25682a5ba65a_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_8d596018-7ae8-4706-9211-25682a5ba65a" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_8d596018-7ae8-4706-9211-25682a5ba65a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_8d1eb143-6757-4b33-9007-14315b99ee07" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_8d596018-7ae8-4706-9211-25682a5ba65a" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_8d1eb143-6757-4b33-9007-14315b99ee07" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateSwapMember_ddd315cc-4300-4d29-b6fe-82da76fbc641" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InterestRateSwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_8d1eb143-6757-4b33-9007-14315b99ee07" xlink:to="loc_us-gaap_InterestRateSwapMember_ddd315cc-4300-4d29-b6fe-82da76fbc641" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignExchangeContractMember_3d36fb6c-d9f8-4b5a-a8d2-c77dcb5305a4" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ForeignExchangeContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_8d1eb143-6757-4b33-9007-14315b99ee07" xlink:to="loc_us-gaap_ForeignExchangeContractMember_3d36fb6c-d9f8-4b5a-a8d2-c77dcb5305a4" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.rackspace.com/role/DerivativesDerivativesPresentedonaNetAssetandNetLiabilitybasisDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#DerivativesDerivativesPresentedonaNetAssetandNetLiabilitybasisDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/DerivativesDerivativesPresentedonaNetAssetandNetLiabilitybasisDetails" xlink:type="extended" id="icab506a592b340dd90b5fc971bc83063_DerivativesDerivativesPresentedonaNetAssetandNetLiabilitybasisDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLineItems_3d9557e4-f069-45bd-9998-a1d60bee180c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssetFairValueOffsetAgainstCollateralNetOfNotSubjectToMasterNettingArrangementPolicyElectionAbstract_2b917afb-b4a1-4bbe-be3c-6a7613cde408" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeAssetFairValueOffsetAgainstCollateralNetOfNotSubjectToMasterNettingArrangementPolicyElectionAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_3d9557e4-f069-45bd-9998-a1d60bee180c" xlink:to="loc_us-gaap_DerivativeAssetFairValueOffsetAgainstCollateralNetOfNotSubjectToMasterNettingArrangementPolicyElectionAbstract_2b917afb-b4a1-4bbe-be3c-6a7613cde408" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssets_6055787d-2b27-4f51-b9e4-5f7cd844d152" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeAssetFairValueOffsetAgainstCollateralNetOfNotSubjectToMasterNettingArrangementPolicyElectionAbstract_2b917afb-b4a1-4bbe-be3c-6a7613cde408" xlink:to="loc_us-gaap_DerivativeAssets_6055787d-2b27-4f51-b9e4-5f7cd844d152" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssetNotOffsetPolicyElectionDeduction_bc9136ba-25d9-4218-aa4e-31e4d28a62eb" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeAssetNotOffsetPolicyElectionDeduction"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeAssetFairValueOffsetAgainstCollateralNetOfNotSubjectToMasterNettingArrangementPolicyElectionAbstract_2b917afb-b4a1-4bbe-be3c-6a7613cde408" xlink:to="loc_us-gaap_DerivativeAssetNotOffsetPolicyElectionDeduction_bc9136ba-25d9-4218-aa4e-31e4d28a62eb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssetFairValueOffsetAgainstCollateralNetOfNotSubjectToMasterNettingArrangementPolicyElection_6275ea83-f6e4-4df7-9e61-49839db20ffb" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeAssetFairValueOffsetAgainstCollateralNetOfNotSubjectToMasterNettingArrangementPolicyElection"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeAssetFairValueOffsetAgainstCollateralNetOfNotSubjectToMasterNettingArrangementPolicyElectionAbstract_2b917afb-b4a1-4bbe-be3c-6a7613cde408" xlink:to="loc_us-gaap_DerivativeAssetFairValueOffsetAgainstCollateralNetOfNotSubjectToMasterNettingArrangementPolicyElection_6275ea83-f6e4-4df7-9e61-49839db20ffb" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilityFairValueOffsetAgainstCollateralNetOfNotSubjectToMasterNettingArrangementPolicyElectionAbstract_88bce28c-f6a5-4003-8351-803f1acda654" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeLiabilityFairValueOffsetAgainstCollateralNetOfNotSubjectToMasterNettingArrangementPolicyElectionAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_3d9557e4-f069-45bd-9998-a1d60bee180c" xlink:to="loc_us-gaap_DerivativeLiabilityFairValueOffsetAgainstCollateralNetOfNotSubjectToMasterNettingArrangementPolicyElectionAbstract_88bce28c-f6a5-4003-8351-803f1acda654" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilities_a951c0ce-e114-4079-a48f-848610389d93" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLiabilityFairValueOffsetAgainstCollateralNetOfNotSubjectToMasterNettingArrangementPolicyElectionAbstract_88bce28c-f6a5-4003-8351-803f1acda654" xlink:to="loc_us-gaap_DerivativeLiabilities_a951c0ce-e114-4079-a48f-848610389d93" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilityNotOffsetPolicyElectionDeduction_7a7cb2a6-ccad-4bb3-bbee-f410ef7eaac2" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeLiabilityNotOffsetPolicyElectionDeduction"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLiabilityFairValueOffsetAgainstCollateralNetOfNotSubjectToMasterNettingArrangementPolicyElectionAbstract_88bce28c-f6a5-4003-8351-803f1acda654" xlink:to="loc_us-gaap_DerivativeLiabilityNotOffsetPolicyElectionDeduction_7a7cb2a6-ccad-4bb3-bbee-f410ef7eaac2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilityFairValueOffsetAgainstCollateralNetOfNotSubjectToMasterNettingArrangementPolicyElection_d14873ab-bffc-42e9-922f-2fdd4352b24d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeLiabilityFairValueOffsetAgainstCollateralNetOfNotSubjectToMasterNettingArrangementPolicyElection"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLiabilityFairValueOffsetAgainstCollateralNetOfNotSubjectToMasterNettingArrangementPolicyElectionAbstract_88bce28c-f6a5-4003-8351-803f1acda654" xlink:to="loc_us-gaap_DerivativeLiabilityFairValueOffsetAgainstCollateralNetOfNotSubjectToMasterNettingArrangementPolicyElection_d14873ab-bffc-42e9-922f-2fdd4352b24d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeTable_0cbf9e7d-7a51-4398-aad8-9be9b39a13c0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeLineItems_3d9557e4-f069-45bd-9998-a1d60bee180c" xlink:to="loc_us-gaap_DerivativeTable_0cbf9e7d-7a51-4398-aad8-9be9b39a13c0" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_756b40ca-951b-41b1-869c-82b8f30ec9a4" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_0cbf9e7d-7a51-4398-aad8-9be9b39a13c0" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_756b40ca-951b-41b1-869c-82b8f30ec9a4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_756b40ca-951b-41b1-869c-82b8f30ec9a4_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_756b40ca-951b-41b1-869c-82b8f30ec9a4" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_756b40ca-951b-41b1-869c-82b8f30ec9a4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_5121f7ba-9598-454d-a90d-02381941f231" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_756b40ca-951b-41b1-869c-82b8f30ec9a4" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_5121f7ba-9598-454d-a90d-02381941f231" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateSwapMember_80671c88-d802-4c1d-9172-0d82adb8680d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InterestRateSwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_5121f7ba-9598-454d-a90d-02381941f231" xlink:to="loc_us-gaap_InterestRateSwapMember_80671c88-d802-4c1d-9172-0d82adb8680d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignExchangeContractMember_1538e0a5-6b46-4e3b-a3c9-da709d1f504a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ForeignExchangeContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_5121f7ba-9598-454d-a90d-02381941f231" xlink:to="loc_us-gaap_ForeignExchangeContractMember_1538e0a5-6b46-4e3b-a3c9-da709d1f504a" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.rackspace.com/role/DerivativesEffectofDerivativesontheConsolidatedStatementsofComprehensiveIncomeLossDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#DerivativesEffectofDerivativesontheConsolidatedStatementsofComprehensiveIncomeLossDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/DerivativesEffectofDerivativesontheConsolidatedStatementsofComprehensiveIncomeLossDetails" xlink:type="extended" id="i3605ef59db814298b90aac3419422767_DerivativesEffectofDerivativesontheConsolidatedStatementsofComprehensiveIncomeLossDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems_f1419827-c7b6-4220-a15a-652755cd05c1" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet_7cb0729a-fff5-4f63-87d3-7ecd91a1c4e8" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems_f1419827-c7b6-4220-a15a-652755cd05c1" xlink:to="loc_us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet_7cb0729a-fff5-4f63-87d3-7ecd91a1c4e8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax_caaa7a6e-f4bd-42ab-9343-a527213cf948" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems_f1419827-c7b6-4220-a15a-652755cd05c1" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax_caaa7a6e-f4bd-42ab-9343-a527213cf948" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_65951159-ecb0-4da5-abd0-959fc9ec6288" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems_f1419827-c7b6-4220-a15a-652755cd05c1" xlink:to="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_65951159-ecb0-4da5-abd0-959fc9ec6288" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_8452d006-3d9a-4814-8183-df3f5450b811" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeStatementLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_65951159-ecb0-4da5-abd0-959fc9ec6288" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_8452d006-3d9a-4814-8183-df3f5450b811" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_8452d006-3d9a-4814-8183-df3f5450b811_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_8452d006-3d9a-4814-8183-df3f5450b811" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_8452d006-3d9a-4814-8183-df3f5450b811_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_f14deae9-b1cb-4d1e-9fb6-f9385078971f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_8452d006-3d9a-4814-8183-df3f5450b811" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_f14deae9-b1cb-4d1e-9fb6-f9385078971f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseMember_7c6ab149-fd2d-4ed8-b22d-e78bee42b3bf" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InterestExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_f14deae9-b1cb-4d1e-9fb6-f9385078971f" xlink:to="loc_us-gaap_InterestExpenseMember_7c6ab149-fd2d-4ed8-b22d-e78bee42b3bf" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfSalesMember_92047190-efa9-4502-acb8-bf35ec10865b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CostOfSalesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_f14deae9-b1cb-4d1e-9fb6-f9385078971f" xlink:to="loc_us-gaap_CostOfSalesMember_92047190-efa9-4502-acb8-bf35ec10865b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpenseMember_408a379a-75ff-4e58-8072-61642782c1c4" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherNonoperatingIncomeExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_f14deae9-b1cb-4d1e-9fb6-f9385078971f" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpenseMember_408a379a-75ff-4e58-8072-61642782c1c4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_e6b5c9a2-7383-4c8b-9417-3364bd56c4ba" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_65951159-ecb0-4da5-abd0-959fc9ec6288" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_e6b5c9a2-7383-4c8b-9417-3364bd56c4ba" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_e6b5c9a2-7383-4c8b-9417-3364bd56c4ba_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_e6b5c9a2-7383-4c8b-9417-3364bd56c4ba" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_e6b5c9a2-7383-4c8b-9417-3364bd56c4ba_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_a20242c8-4da9-4170-a064-5232ba66ab6c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_e6b5c9a2-7383-4c8b-9417-3364bd56c4ba" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_a20242c8-4da9-4170-a064-5232ba66ab6c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateSwapMember_9dd26d20-0bfe-4450-98ec-727cedf53edc" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InterestRateSwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_a20242c8-4da9-4170-a064-5232ba66ab6c" xlink:to="loc_us-gaap_InterestRateSwapMember_9dd26d20-0bfe-4450-98ec-727cedf53edc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EnergyRelatedDerivativeMember_2555a79c-f7ab-4344-a8b2-8f67d0bbbd24" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EnergyRelatedDerivativeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_a20242c8-4da9-4170-a064-5232ba66ab6c" xlink:to="loc_us-gaap_EnergyRelatedDerivativeMember_2555a79c-f7ab-4344-a8b2-8f67d0bbbd24" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignExchangeForwardMember_9461d8eb-f290-4ee1-8de5-780a8aa631cc" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ForeignExchangeForwardMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_a20242c8-4da9-4170-a064-5232ba66ab6c" xlink:to="loc_us-gaap_ForeignExchangeForwardMember_9461d8eb-f290-4ee1-8de5-780a8aa631cc" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.rackspace.com/role/AccumulatedOtherComprehensiveIncomeLoss" xlink:type="simple" xlink:href="rxt-20201231.xsd#AccumulatedOtherComprehensiveIncomeLoss"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/AccumulatedOtherComprehensiveIncomeLoss" xlink:type="extended" id="i2ef2a341647a422291375be9dc8b5381_AccumulatedOtherComprehensiveIncomeLoss"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/AccumulatedOtherComprehensiveIncomeLossTables" xlink:type="simple" xlink:href="rxt-20201231.xsd#AccumulatedOtherComprehensiveIncomeLossTables"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/AccumulatedOtherComprehensiveIncomeLossTables" xlink:type="extended" id="i7e36d958afe64f7a977e9d765b6e7ed5_AccumulatedOtherComprehensiveIncomeLossTables"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/AccumulatedOtherComprehensiveIncomeLossScheduleofAccumulatedOtherComprehensiveIncomeLossDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#AccumulatedOtherComprehensiveIncomeLossScheduleofAccumulatedOtherComprehensiveIncomeLossDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/AccumulatedOtherComprehensiveIncomeLossScheduleofAccumulatedOtherComprehensiveIncomeLossDetails" xlink:type="extended" id="ied864a198b6c4587b184eb39062c8354_AccumulatedOtherComprehensiveIncomeLossScheduleofAccumulatedOtherComprehensiveIncomeLossDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_2f05ea9b-e8ed-4eca-9a59-deed3cbc5f52" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_526b2573-7f6a-4588-b608-635c7c8470e5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AOCIAttributableToParentNetOfTaxRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_2f05ea9b-e8ed-4eca-9a59-deed3cbc5f52" xlink:to="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_526b2573-7f6a-4588-b608-635c7c8470e5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_0ea4178b-6df3-473c-b81f-8412201fda7d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_526b2573-7f6a-4588-b608-635c7c8470e5" xlink:to="loc_us-gaap_StockholdersEquity_0ea4178b-6df3-473c-b81f-8412201fda7d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent_fc9e417a-d9a2-4aa0-928b-ed3a7bd9efc6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_526b2573-7f6a-4588-b608-635c7c8470e5" xlink:to="loc_us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent_fc9e417a-d9a2-4aa0-928b-ed3a7bd9efc6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax_eb33453d-74cb-45d7-a2a4-ff8b9ec485b5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_526b2573-7f6a-4588-b608-635c7c8470e5" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax_eb33453d-74cb-45d7-a2a4-ff8b9ec485b5" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax_a4af83e2-152a-4dbc-8ee7-1cdc811b6315" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_526b2573-7f6a-4588-b608-635c7c8470e5" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax_a4af83e2-152a-4dbc-8ee7-1cdc811b6315" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_7652421b-105f-44cd-8ea7-5577a72cc3f5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeForeignCurrencyTranslationAdjustmentTaxPortionAttributableToParent_959fd08a-ceec-4eee-9ded-5daa81aef94c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeForeignCurrencyTranslationAdjustmentTaxPortionAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_2f05ea9b-e8ed-4eca-9a59-deed3cbc5f52" xlink:to="loc_us-gaap_OtherComprehensiveIncomeForeignCurrencyTranslationAdjustmentTaxPortionAttributableToParent_959fd08a-ceec-4eee-9ded-5daa81aef94c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationTax_b17fd97b-20d1-4f0c-8d48-39b7e298ce1d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_2f05ea9b-e8ed-4eca-9a59-deed3cbc5f52" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationTax_b17fd97b-20d1-4f0c-8d48-39b7e298ce1d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationTax_10a87c58-dba0-45f7-abe6-cde55b96f611" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_2f05ea9b-e8ed-4eca-9a59-deed3cbc5f52" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationTax_10a87c58-dba0-45f7-abe6-cde55b96f611" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpense_85a55caf-dc2d-43e0-8492-bb8dc82c43bd" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InterestExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_2f05ea9b-e8ed-4eca-9a59-deed3cbc5f52" xlink:to="loc_us-gaap_InterestExpense_85a55caf-dc2d-43e0-8492-bb8dc82c43bd" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_InterestExpenseAmortizationOfOffMarketSwapOffset_f6c92dce-f017-4cac-94ba-abf453f44363" xlink:href="rxt-20201231.xsd#rxt_InterestExpenseAmortizationOfOffMarketSwapOffset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_2f05ea9b-e8ed-4eca-9a59-deed3cbc5f52" xlink:to="loc_rxt_InterestExpenseAmortizationOfOffMarketSwapOffset_f6c92dce-f017-4cac-94ba-abf453f44363" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_c8bbcf58-25aa-4b24-8830-c117f9e4e15d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_2f05ea9b-e8ed-4eca-9a59-deed3cbc5f52" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_c8bbcf58-25aa-4b24-8830-c117f9e4e15d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_3aff8fac-42fa-4d61-a280-7ebf2fcbde3a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_c8bbcf58-25aa-4b24-8830-c117f9e4e15d" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_3aff8fac-42fa-4d61-a280-7ebf2fcbde3a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_3aff8fac-42fa-4d61-a280-7ebf2fcbde3a_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_3aff8fac-42fa-4d61-a280-7ebf2fcbde3a" xlink:to="loc_us-gaap_EquityComponentDomain_3aff8fac-42fa-4d61-a280-7ebf2fcbde3a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_77f1b6ba-24eb-48fc-9da9-1051be5c2363" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_3aff8fac-42fa-4d61-a280-7ebf2fcbde3a" xlink:to="loc_us-gaap_EquityComponentDomain_77f1b6ba-24eb-48fc-9da9-1051be5c2363" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedTranslationAdjustmentMember_ef8767b3-19c2-4701-ae6c-167254f508d4" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedTranslationAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_77f1b6ba-24eb-48fc-9da9-1051be5c2363" xlink:to="loc_us-gaap_AccumulatedTranslationAdjustmentMember_ef8767b3-19c2-4701-ae6c-167254f508d4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_dabdaaa4-d310-43b7-86de-0eea98e1b99a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_77f1b6ba-24eb-48fc-9da9-1051be5c2363" xlink:to="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_dabdaaa4-d310-43b7-86de-0eea98e1b99a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_d04d05a8-239d-43f5-a1f6-2c2737f2acbc" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_77f1b6ba-24eb-48fc-9da9-1051be5c2363" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_d04d05a8-239d-43f5-a1f6-2c2737f2acbc" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis_a56f9f3d-240e-4c4f-8e6b-1099cb3fd36d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_c8bbcf58-25aa-4b24-8830-c117f9e4e15d" xlink:to="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis_a56f9f3d-240e-4c4f-8e6b-1099cb3fd36d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain_a56f9f3d-240e-4c4f-8e6b-1099cb3fd36d_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis_a56f9f3d-240e-4c4f-8e6b-1099cb3fd36d" xlink:to="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain_a56f9f3d-240e-4c4f-8e6b-1099cb3fd36d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain_e910cf75-7b6d-46ed-8ded-6c41cb1e132a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis_a56f9f3d-240e-4c4f-8e6b-1099cb3fd36d" xlink:to="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain_e910cf75-7b6d-46ed-8ded-6c41cb1e132a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember_91d2459b-45ce-42b1-9eaf-f514c0c1b684" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain_e910cf75-7b6d-46ed-8ded-6c41cb1e132a" xlink:to="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember_91d2459b-45ce-42b1-9eaf-f514c0c1b684" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.rackspace.com/role/RelatedPartyTransactions" xlink:type="simple" xlink:href="rxt-20201231.xsd#RelatedPartyTransactions"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/RelatedPartyTransactions" xlink:type="extended" id="i3e85999f76054b1f87399aa11de61688_RelatedPartyTransactions"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/RelatedPartyTransactionsNarrativeDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#RelatedPartyTransactionsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/RelatedPartyTransactionsNarrativeDetails" xlink:type="extended" id="i300af01da5ce405c9ddf66b97a5f7d65_RelatedPartyTransactionsNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionLineItems_1216c0b0-5f4a-4982-b341-31defbb861b6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RelatedPartyTransactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_RelatedPartyTransactionConsultingFeePercentageOfEBITDA_1967f2ff-edf0-4c7a-9e75-5309fd601344" xlink:href="rxt-20201231.xsd#rxt_RelatedPartyTransactionConsultingFeePercentageOfEBITDA"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_1216c0b0-5f4a-4982-b341-31defbb861b6" xlink:to="loc_rxt_RelatedPartyTransactionConsultingFeePercentageOfEBITDA_1967f2ff-edf0-4c7a-9e75-5309fd601344" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionAmountsOfTransaction_cbd177f4-042b-46c9-81d9-9b6b3b8a9236" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RelatedPartyTransactionAmountsOfTransaction"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_1216c0b0-5f4a-4982-b341-31defbb861b6" xlink:to="loc_us-gaap_RelatedPartyTransactionAmountsOfTransaction_cbd177f4-042b-46c9-81d9-9b6b3b8a9236" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionSellingGeneralAndAdministrativeExpensesFromTransactionsWithRelatedParty_512355cc-fc3c-4a60-9efb-ffa8b3cbc46e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RelatedPartyTransactionSellingGeneralAndAdministrativeExpensesFromTransactionsWithRelatedParty"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_1216c0b0-5f4a-4982-b341-31defbb861b6" xlink:to="loc_us-gaap_RelatedPartyTransactionSellingGeneralAndAdministrativeExpensesFromTransactionsWithRelatedParty_512355cc-fc3c-4a60-9efb-ffa8b3cbc46e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_e4938b14-fbc2-4d6a-93e6-aa78a57ed1bf" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_1216c0b0-5f4a-4982-b341-31defbb861b6" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_e4938b14-fbc2-4d6a-93e6-aa78a57ed1bf" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_PercentageOfOutstandingPrincipalAmountDueToRelatedParty_3e66b507-3c1a-4b11-8009-f9ef3ce08499" xlink:href="rxt-20201231.xsd#rxt_PercentageOfOutstandingPrincipalAmountDueToRelatedParty"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_1216c0b0-5f4a-4982-b341-31defbb861b6" xlink:to="loc_rxt_PercentageOfOutstandingPrincipalAmountDueToRelatedParty_3e66b507-3c1a-4b11-8009-f9ef3ce08499" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_cf1dd86b-e944-4691-a096-5dc478f22a52" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_1216c0b0-5f4a-4982-b341-31defbb861b6" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_cf1dd86b-e944-4691-a096-5dc478f22a52" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_1c17a15e-11a0-4693-98ed-7fdd1bd5dfe9" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_1216c0b0-5f4a-4982-b341-31defbb861b6" xlink:to="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_1c17a15e-11a0-4693-98ed-7fdd1bd5dfe9" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_212cbd65-876e-4481-bd55-b197597a9183" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_1c17a15e-11a0-4693-98ed-7fdd1bd5dfe9" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_212cbd65-876e-4481-bd55-b197597a9183" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_212cbd65-876e-4481-bd55-b197597a9183_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_212cbd65-876e-4481-bd55-b197597a9183" xlink:to="loc_us-gaap_RelatedPartyDomain_212cbd65-876e-4481-bd55-b197597a9183_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_fb6788ba-8bf6-4a8f-98c6-057ab9440598" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_212cbd65-876e-4481-bd55-b197597a9183" xlink:to="loc_us-gaap_RelatedPartyDomain_fb6788ba-8bf6-4a8f-98c6-057ab9440598" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AffiliatedEntityMember_fa82f4ec-8b7c-405c-b15e-193ae9b90850" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_AffiliatedEntityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_fb6788ba-8bf6-4a8f-98c6-057ab9440598" xlink:to="loc_srt_AffiliatedEntityMember_fa82f4ec-8b7c-405c-b15e-193ae9b90850" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionAxis_949b91ae-cad3-4cd3-b35e-85fb73bfccf0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RelatedPartyTransactionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_1c17a15e-11a0-4693-98ed-7fdd1bd5dfe9" xlink:to="loc_us-gaap_RelatedPartyTransactionAxis_949b91ae-cad3-4cd3-b35e-85fb73bfccf0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionDomain_949b91ae-cad3-4cd3-b35e-85fb73bfccf0_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RelatedPartyTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionAxis_949b91ae-cad3-4cd3-b35e-85fb73bfccf0" xlink:to="loc_us-gaap_RelatedPartyTransactionDomain_949b91ae-cad3-4cd3-b35e-85fb73bfccf0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionDomain_2de83daf-c965-46cc-a1ca-65e8872e8f1a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RelatedPartyTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionAxis_949b91ae-cad3-4cd3-b35e-85fb73bfccf0" xlink:to="loc_us-gaap_RelatedPartyTransactionDomain_2de83daf-c965-46cc-a1ca-65e8872e8f1a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_ConsultingFeesMember_a97ad69d-8660-49cb-b1ea-986bbbb600a9" xlink:href="rxt-20201231.xsd#rxt_ConsultingFeesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionDomain_2de83daf-c965-46cc-a1ca-65e8872e8f1a" xlink:to="loc_rxt_ConsultingFeesMember_a97ad69d-8660-49cb-b1ea-986bbbb600a9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_MinimumAnnualConsultingFeesMember_4c3e6d87-a1db-43d2-a91b-720c90f314d2" xlink:href="rxt-20201231.xsd#rxt_MinimumAnnualConsultingFeesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionDomain_2de83daf-c965-46cc-a1ca-65e8872e8f1a" xlink:to="loc_rxt_MinimumAnnualConsultingFeesMember_4c3e6d87-a1db-43d2-a91b-720c90f314d2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_SeniorNotesReceivedMember_bcf4ac98-d7ce-4250-9715-605e9fa9f82a" xlink:href="rxt-20201231.xsd#rxt_SeniorNotesReceivedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionDomain_2de83daf-c965-46cc-a1ca-65e8872e8f1a" xlink:to="loc_rxt_SeniorNotesReceivedMember_bcf4ac98-d7ce-4250-9715-605e9fa9f82a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CounterpartyNameAxis_e4ddc456-07da-4246-9030-d677016a3ee9" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_CounterpartyNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_1c17a15e-11a0-4693-98ed-7fdd1bd5dfe9" xlink:to="loc_srt_CounterpartyNameAxis_e4ddc456-07da-4246-9030-d677016a3ee9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_e4ddc456-07da-4246-9030-d677016a3ee9_default" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_CounterpartyNameAxis_e4ddc456-07da-4246-9030-d677016a3ee9" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_e4ddc456-07da-4246-9030-d677016a3ee9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_4a016864-90f5-4f14-ad60-61e6add5cf32" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_CounterpartyNameAxis_e4ddc456-07da-4246-9030-d677016a3ee9" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_4a016864-90f5-4f14-ad60-61e6add5cf32" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_ApolloAndSearchlightMember_5b71d2fe-8d51-4861-8a85-317a362878a0" xlink:href="rxt-20201231.xsd#rxt_ApolloAndSearchlightMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_4a016864-90f5-4f14-ad60-61e6add5cf32" xlink:to="loc_rxt_ApolloAndSearchlightMember_5b71d2fe-8d51-4861-8a85-317a362878a0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_ABRYMember_1d6c4771-c0f3-4d71-99eb-1e50c1ad3a7a" xlink:href="rxt-20201231.xsd#rxt_ABRYMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_4a016864-90f5-4f14-ad60-61e6add5cf32" xlink:to="loc_rxt_ABRYMember_1d6c4771-c0f3-4d71-99eb-1e50c1ad3a7a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_AffiliatesOfABRYMember_6cf7305f-1ba7-47e5-a498-816cde07b854" xlink:href="rxt-20201231.xsd#rxt_AffiliatesOfABRYMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_4a016864-90f5-4f14-ad60-61e6add5cf32" xlink:to="loc_rxt_AffiliatesOfABRYMember_6cf7305f-1ba7-47e5-a498-816cde07b854" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_ApolloGlobalSecuritiesLLCMember_f65c21a9-64cf-48a1-9446-6a40b106ec93" xlink:href="rxt-20201231.xsd#rxt_ApolloGlobalSecuritiesLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_4a016864-90f5-4f14-ad60-61e6add5cf32" xlink:to="loc_rxt_ApolloGlobalSecuritiesLLCMember_f65c21a9-64cf-48a1-9446-6a40b106ec93" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_ApolloSearchlightAndABRYMember_e98171ac-d63c-4da3-8eec-cc5e6b6b845c" xlink:href="rxt-20201231.xsd#rxt_ApolloSearchlightAndABRYMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_4a016864-90f5-4f14-ad60-61e6add5cf32" xlink:to="loc_rxt_ApolloSearchlightAndABRYMember_e98171ac-d63c-4da3-8eec-cc5e6b6b845c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_4d6bbeaa-35e6-4713-b722-8faefe2117ab" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_1c17a15e-11a0-4693-98ed-7fdd1bd5dfe9" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_4d6bbeaa-35e6-4713-b722-8faefe2117ab" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_4d6bbeaa-35e6-4713-b722-8faefe2117ab_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_4d6bbeaa-35e6-4713-b722-8faefe2117ab" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_4d6bbeaa-35e6-4713-b722-8faefe2117ab_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_f83c53b9-c55f-4ae5-9c60-80ad9e501b75" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_4d6bbeaa-35e6-4713-b722-8faefe2117ab" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_f83c53b9-c55f-4ae5-9c60-80ad9e501b75" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebtMember_56ad8171-521b-4e60-9c14-35767d59c357" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_f83c53b9-c55f-4ae5-9c60-80ad9e501b75" xlink:to="loc_us-gaap_SecuredDebtMember_56ad8171-521b-4e60-9c14-35767d59c357" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorNotesMember_fafe380e-f3b6-489c-b122-cebd630449f2" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_f83c53b9-c55f-4ae5-9c60-80ad9e501b75" xlink:to="loc_us-gaap_SeniorNotesMember_fafe380e-f3b6-489c-b122-cebd630449f2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_59dd20d7-fc49-4338-9656-18cd815f4d6d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_1c17a15e-11a0-4693-98ed-7fdd1bd5dfe9" xlink:to="loc_us-gaap_DebtInstrumentAxis_59dd20d7-fc49-4338-9656-18cd815f4d6d" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_59dd20d7-fc49-4338-9656-18cd815f4d6d_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_59dd20d7-fc49-4338-9656-18cd815f4d6d" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_59dd20d7-fc49-4338-9656-18cd815f4d6d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_ba953854-db15-4e98-8116-3c1d9e78a68b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_59dd20d7-fc49-4338-9656-18cd815f4d6d" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_ba953854-db15-4e98-8116-3c1d9e78a68b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_FirstLienCreditAgreementMember_8462c373-ef5b-4e98-a4f6-30f5dcadc9bb" xlink:href="rxt-20201231.xsd#rxt_FirstLienCreditAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_ba953854-db15-4e98-8116-3c1d9e78a68b" xlink:to="loc_rxt_FirstLienCreditAgreementMember_8462c373-ef5b-4e98-a4f6-30f5dcadc9bb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_SeniorNotes5375Due2028Member_d41a7896-799c-4c4a-82a2-a82bf7e7a794" xlink:href="rxt-20201231.xsd#rxt_SeniorNotes5375Due2028Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_ba953854-db15-4e98-8116-3c1d9e78a68b" xlink:to="loc_rxt_SeniorNotes5375Due2028Member_d41a7896-799c-4c4a-82a2-a82bf7e7a794" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsidiarySaleOfStockAxis_0685c84d-4d1b-43ff-8fd9-5feaf6c90dd9" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsidiarySaleOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_1c17a15e-11a0-4693-98ed-7fdd1bd5dfe9" xlink:to="loc_us-gaap_SubsidiarySaleOfStockAxis_0685c84d-4d1b-43ff-8fd9-5feaf6c90dd9" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_0685c84d-4d1b-43ff-8fd9-5feaf6c90dd9_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_0685c84d-4d1b-43ff-8fd9-5feaf6c90dd9" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_0685c84d-4d1b-43ff-8fd9-5feaf6c90dd9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_4b973496-85d1-4d40-8202-53e38359ac73" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_0685c84d-4d1b-43ff-8fd9-5feaf6c90dd9" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_4b973496-85d1-4d40-8202-53e38359ac73" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IPOMember_b7b92d07-8ae8-49a8-a8bc-5b7a675ce75f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IPOMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SaleOfStockNameOfTransactionDomain_4b973496-85d1-4d40-8202-53e38359ac73" xlink:to="loc_us-gaap_IPOMember_b7b92d07-8ae8-49a8-a8bc-5b7a675ce75f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_6c656755-05e1-47f1-bba7-8ea82b4a48da" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_1c17a15e-11a0-4693-98ed-7fdd1bd5dfe9" xlink:to="loc_srt_RangeAxis_6c656755-05e1-47f1-bba7-8ea82b4a48da" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_6c656755-05e1-47f1-bba7-8ea82b4a48da_default" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_6c656755-05e1-47f1-bba7-8ea82b4a48da" xlink:to="loc_srt_RangeMember_6c656755-05e1-47f1-bba7-8ea82b4a48da_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_fd567bb7-aa91-41a2-8e5d-78fd111d9e57" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_6c656755-05e1-47f1-bba7-8ea82b4a48da" xlink:to="loc_srt_RangeMember_fd567bb7-aa91-41a2-8e5d-78fd111d9e57" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_a115747d-0380-4309-98b5-7d94b002c79a" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_fd567bb7-aa91-41a2-8e5d-78fd111d9e57" xlink:to="loc_srt_MinimumMember_a115747d-0380-4309-98b5-7d94b002c79a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_0c02141e-4216-4422-b918-9b4574d1b115" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_1c17a15e-11a0-4693-98ed-7fdd1bd5dfe9" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_0c02141e-4216-4422-b918-9b4574d1b115" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_0c02141e-4216-4422-b918-9b4574d1b115_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_0c02141e-4216-4422-b918-9b4574d1b115" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_0c02141e-4216-4422-b918-9b4574d1b115_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_c06b0a78-ae07-45c5-98aa-65fc90a833c6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_0c02141e-4216-4422-b918-9b4574d1b115" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_c06b0a78-ae07-45c5-98aa-65fc90a833c6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_RelationEdgeLLCMember_a46c0994-7c82-4356-be57-212ee5cf6ffd" xlink:href="rxt-20201231.xsd#rxt_RelationEdgeLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_c06b0a78-ae07-45c5-98aa-65fc90a833c6" xlink:to="loc_rxt_RelationEdgeLLCMember_a46c0994-7c82-4356-be57-212ee5cf6ffd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_OnicaHoldingsLLCMember_746d5f96-445c-4428-a7f7-e4f6b68321e2" xlink:href="rxt-20201231.xsd#rxt_OnicaHoldingsLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_c06b0a78-ae07-45c5-98aa-65fc90a833c6" xlink:to="loc_rxt_OnicaHoldingsLLCMember_746d5f96-445c-4428-a7f7-e4f6b68321e2" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.rackspace.com/role/SegmentReporting" xlink:type="simple" xlink:href="rxt-20201231.xsd#SegmentReporting"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/SegmentReporting" xlink:type="extended" id="i4b12378570ab431ea51b73298e78ac7e_SegmentReporting"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/SegmentReportingTables" xlink:type="simple" xlink:href="rxt-20201231.xsd#SegmentReportingTables"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/SegmentReportingTables" xlink:type="extended" id="i4305fa46431842debd31239f410a16c8_SegmentReportingTables"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/SegmentReportingNarrativeDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#SegmentReportingNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/SegmentReportingNarrativeDetails" xlink:type="extended" id="ic208cc3c9fe643d89edf0030565b6cd2_SegmentReportingNarrativeDetails"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/SegmentReportingReconciliationofRevenueandGrossProfitsfromSegmentstoConsolidatedDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#SegmentReportingReconciliationofRevenueandGrossProfitsfromSegmentstoConsolidatedDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/SegmentReportingReconciliationofRevenueandGrossProfitsfromSegmentstoConsolidatedDetails" xlink:type="extended" id="i50533170798741ba81acab1f7e23f36d_SegmentReportingReconciliationofRevenueandGrossProfitsfromSegmentstoConsolidatedDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingRevenueReconcilingItemLineItems_200651d4-f5eb-4cfc-adf5-e959668f14b1" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SegmentReportingRevenueReconcilingItemLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_a586e668-1e4e-476e-bfe1-808256fe6138" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingRevenueReconcilingItemLineItems_200651d4-f5eb-4cfc-adf5-e959668f14b1" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_a586e668-1e4e-476e-bfe1-808256fe6138" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GrossProfit_34b3416e-809b-47a3-94f3-0fa1ae076bb0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GrossProfit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingRevenueReconcilingItemLineItems_200651d4-f5eb-4cfc-adf5-e959668f14b1" xlink:to="loc_us-gaap_GrossProfit_34b3416e-809b-47a3-94f3-0fa1ae076bb0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_5511c448-a62c-4777-aca8-8e672e767831" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingRevenueReconcilingItemLineItems_200651d4-f5eb-4cfc-adf5-e959668f14b1" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_5511c448-a62c-4777-aca8-8e672e767831" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CompensationExpenseExcludingCostOfGoodAndServiceSold_b2ef4573-b28b-4780-a201-83849c069fb9" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CompensationExpenseExcludingCostOfGoodAndServiceSold"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingRevenueReconcilingItemLineItems_200651d4-f5eb-4cfc-adf5-e959668f14b1" xlink:to="loc_us-gaap_CompensationExpenseExcludingCostOfGoodAndServiceSold_b2ef4573-b28b-4780-a201-83849c069fb9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_BusinessCombinationAcquisitionRelatedRevenueFromPurchaseAccountingAdjustments_64bf65fb-a56c-488d-bce0-3c71f4a06f06" xlink:href="rxt-20201231.xsd#rxt_BusinessCombinationAcquisitionRelatedRevenueFromPurchaseAccountingAdjustments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingRevenueReconcilingItemLineItems_200651d4-f5eb-4cfc-adf5-e959668f14b1" xlink:to="loc_rxt_BusinessCombinationAcquisitionRelatedRevenueFromPurchaseAccountingAdjustments_64bf65fb-a56c-488d-bce0-3c71f4a06f06" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_BusinessCombinationAcquisitionRelatedExpenseFromPurchaseAccountingAdjustments_4a7962a4-b1d7-4e13-92ee-7c1f348b6c33" xlink:href="rxt-20201231.xsd#rxt_BusinessCombinationAcquisitionRelatedExpenseFromPurchaseAccountingAdjustments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingRevenueReconcilingItemLineItems_200651d4-f5eb-4cfc-adf5-e959668f14b1" xlink:to="loc_rxt_BusinessCombinationAcquisitionRelatedExpenseFromPurchaseAccountingAdjustments_4a7962a4-b1d7-4e13-92ee-7c1f348b6c33" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCharges_52a825a0-20c5-40a9-9fc0-e8e1a533e73d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestructuringCharges"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingRevenueReconcilingItemLineItems_200651d4-f5eb-4cfc-adf5-e959668f14b1" xlink:to="loc_us-gaap_RestructuringCharges_52a825a0-20c5-40a9-9fc0-e8e1a533e73d" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReconciliationOfRevenueFromSegmentsToConsolidatedTable_5560017f-5289-4873-9286-e5419b9893a3" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ReconciliationOfRevenueFromSegmentsToConsolidatedTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingRevenueReconcilingItemLineItems_200651d4-f5eb-4cfc-adf5-e959668f14b1" xlink:to="loc_us-gaap_ReconciliationOfRevenueFromSegmentsToConsolidatedTable_5560017f-5289-4873-9286-e5419b9893a3" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_970080c3-d117-4611-88d8-d71dec1c8dc3" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ReconciliationOfRevenueFromSegmentsToConsolidatedTable_5560017f-5289-4873-9286-e5419b9893a3" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_970080c3-d117-4611-88d8-d71dec1c8dc3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_970080c3-d117-4611-88d8-d71dec1c8dc3_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_970080c3-d117-4611-88d8-d71dec1c8dc3" xlink:to="loc_us-gaap_SegmentDomain_970080c3-d117-4611-88d8-d71dec1c8dc3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_db7889d4-8bc9-40cf-8318-d3a779fb0124" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_970080c3-d117-4611-88d8-d71dec1c8dc3" xlink:to="loc_us-gaap_SegmentDomain_db7889d4-8bc9-40cf-8318-d3a779fb0124" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_MultiCloudServicesSegmentMember_572715df-31d5-4031-9401-c84f4a08a907" xlink:href="rxt-20201231.xsd#rxt_MultiCloudServicesSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_db7889d4-8bc9-40cf-8318-d3a779fb0124" xlink:to="loc_rxt_MultiCloudServicesSegmentMember_572715df-31d5-4031-9401-c84f4a08a907" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_AppsCrossPlatformSegmentMember_b3cb8020-bc69-45d5-8d32-564b44fc2ba3" xlink:href="rxt-20201231.xsd#rxt_AppsCrossPlatformSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_db7889d4-8bc9-40cf-8318-d3a779fb0124" xlink:to="loc_rxt_AppsCrossPlatformSegmentMember_b3cb8020-bc69-45d5-8d32-564b44fc2ba3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_OpenStackPublicCloudSegmentMember_8da621be-fdb8-4bd7-b595-d5b58a6a28b4" xlink:href="rxt-20201231.xsd#rxt_OpenStackPublicCloudSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_db7889d4-8bc9-40cf-8318-d3a779fb0124" xlink:to="loc_rxt_OpenStackPublicCloudSegmentMember_8da621be-fdb8-4bd7-b595-d5b58a6a28b4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_43099ca9-e14e-4c3a-94d8-3c65e0ff13ac" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeStatementLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ReconciliationOfRevenueFromSegmentsToConsolidatedTable_5560017f-5289-4873-9286-e5419b9893a3" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_43099ca9-e14e-4c3a-94d8-3c65e0ff13ac" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_43099ca9-e14e-4c3a-94d8-3c65e0ff13ac_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_43099ca9-e14e-4c3a-94d8-3c65e0ff13ac" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_43099ca9-e14e-4c3a-94d8-3c65e0ff13ac_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_688edc24-7ee2-45e6-8ad3-8ac2d868600c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_43099ca9-e14e-4c3a-94d8-3c65e0ff13ac" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_688edc24-7ee2-45e6-8ad3-8ac2d868600c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfSalesMember_f72cc2bb-af2e-4504-b214-d5ea42af7179" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CostOfSalesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_688edc24-7ee2-45e6-8ad3-8ac2d868600c" xlink:to="loc_us-gaap_CostOfSalesMember_f72cc2bb-af2e-4504-b214-d5ea42af7179" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.rackspace.com/role/SegmentReportingGeographicInformationDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#SegmentReportingGeographicInformationDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/SegmentReportingGeographicInformationDetails" xlink:type="extended" id="i8a13718994ca49a1bcbf1b7b70f2ee83_SegmentReportingGeographicInformationDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_35cd8db7-4a63-4e3d-b410-2d463ed24436" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_8e880e02-a2e7-4cfb-9a84-983ff0a35bbe" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_35cd8db7-4a63-4e3d-b410-2d463ed24436" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_8e880e02-a2e7-4cfb-9a84-983ff0a35bbe" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization_ab021730-381f-46aa-ac85-03f3e344453d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_35cd8db7-4a63-4e3d-b410-2d463ed24436" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization_ab021730-381f-46aa-ac85-03f3e344453d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_74ca1a03-a6c7-433a-a99f-cbd867e0cd70" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_35cd8db7-4a63-4e3d-b410-2d463ed24436" xlink:to="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_74ca1a03-a6c7-433a-a99f-cbd867e0cd70" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_605981c8-c3cd-4190-a25d-11c0406cbcec" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_74ca1a03-a6c7-433a-a99f-cbd867e0cd70" xlink:to="loc_srt_StatementGeographicalAxis_605981c8-c3cd-4190-a25d-11c0406cbcec" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_605981c8-c3cd-4190-a25d-11c0406cbcec_default" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_605981c8-c3cd-4190-a25d-11c0406cbcec" xlink:to="loc_srt_SegmentGeographicalDomain_605981c8-c3cd-4190-a25d-11c0406cbcec_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_307c8c8f-67f5-439a-8ec9-9d785414c470" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_605981c8-c3cd-4190-a25d-11c0406cbcec" xlink:to="loc_srt_SegmentGeographicalDomain_307c8c8f-67f5-439a-8ec9-9d785414c470" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AmericasMember_1c1b65c1-e3b0-49c3-bdaa-15fe27de09b8" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_AmericasMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_307c8c8f-67f5-439a-8ec9-9d785414c470" xlink:to="loc_srt_AmericasMember_1c1b65c1-e3b0-49c3-bdaa-15fe27de09b8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_5902ff31-3b43-49f8-bb4d-06a7d3071043" xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_AmericasMember_1c1b65c1-e3b0-49c3-bdaa-15fe27de09b8" xlink:to="loc_country_US_5902ff31-3b43-49f8-bb4d-06a7d3071043" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EMEAMember_5b828c67-6981-4179-8a05-2734a5804b6c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EMEAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_307c8c8f-67f5-439a-8ec9-9d785414c470" xlink:to="loc_us-gaap_EMEAMember_5b828c67-6981-4179-8a05-2734a5804b6c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_GB_e4801204-0892-4b77-83eb-470883476748" xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_GB"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EMEAMember_5b828c67-6981-4179-8a05-2734a5804b6c" xlink:to="loc_country_GB_e4801204-0892-4b77-83eb-470883476748" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AsiaPacificMember_ab9ff3a8-ece6-4335-b004-d490c83102e8" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_AsiaPacificMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_307c8c8f-67f5-439a-8ec9-9d785414c470" xlink:to="loc_srt_AsiaPacificMember_ab9ff3a8-ece6-4335-b004-d490c83102e8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_OtherForeignCountriesMember_2e576682-1480-4024-80ea-c16de83d9bd4" xlink:href="rxt-20201231.xsd#rxt_OtherForeignCountriesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_307c8c8f-67f5-439a-8ec9-9d785414c470" xlink:to="loc_rxt_OtherForeignCountriesMember_2e576682-1480-4024-80ea-c16de83d9bd4" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.rackspace.com/role/CondensedFinancialInformationofRegistrantParentCompanyOnly" xlink:type="simple" xlink:href="rxt-20201231.xsd#CondensedFinancialInformationofRegistrantParentCompanyOnly"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/CondensedFinancialInformationofRegistrantParentCompanyOnly" xlink:type="extended" id="ie5bfe868a31045439e2875d0a2351334_CondensedFinancialInformationofRegistrantParentCompanyOnly"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/CondensedFinancialInformationofRegistrantParentCompanyOnlyTables" xlink:type="simple" xlink:href="rxt-20201231.xsd#CondensedFinancialInformationofRegistrantParentCompanyOnlyTables"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/CondensedFinancialInformationofRegistrantParentCompanyOnlyTables" xlink:type="extended" id="i3c2acb52f72040848f632b73fdcb063a_CondensedFinancialInformationofRegistrantParentCompanyOnlyTables"/>
  <link:roleRef roleURI="http://www.rackspace.com/role/CondensedFinancialInformationofRegistrantParentCompanyOnlyCondensedBalanceSheetsDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#CondensedFinancialInformationofRegistrantParentCompanyOnlyCondensedBalanceSheetsDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/CondensedFinancialInformationofRegistrantParentCompanyOnlyCondensedBalanceSheetsDetails" xlink:type="extended" id="i252f9fb285344d6489d0eea206d3499d_CondensedFinancialInformationofRegistrantParentCompanyOnlyCondensedBalanceSheetsDetails">
    <link:loc xlink:type="locator" xlink:label="loc_srt_CondensedBalanceSheetStatementsCaptionsLineItems_5c53b79e-cd18-4d84-b845-68d2e0c0a018" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_CondensedBalanceSheetStatementsCaptionsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsAbstract_24f2a1f2-961e-4dad-beaa-713813e5c499" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AssetsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_CondensedBalanceSheetStatementsCaptionsLineItems_5c53b79e-cd18-4d84-b845-68d2e0c0a018" xlink:to="loc_us-gaap_AssetsAbstract_24f2a1f2-961e-4dad-beaa-713813e5c499" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_InvestmentsInSubsidiaries_ee49baf6-a160-44f0-808a-837802116325" xlink:href="rxt-20201231.xsd#rxt_InvestmentsInSubsidiaries"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_24f2a1f2-961e-4dad-beaa-713813e5c499" xlink:to="loc_rxt_InvestmentsInSubsidiaries_ee49baf6-a160-44f0-808a-837802116325" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_e1caf72e-d16b-4106-9e77-7e8277243c2c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Assets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_24f2a1f2-961e-4dad-beaa-713813e5c499" xlink:to="loc_us-gaap_Assets_e1caf72e-d16b-4106-9e77-7e8277243c2c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAbstract_44973fc9-71f2-4c73-b3fc-bfca3f5be670" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LiabilitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_CondensedBalanceSheetStatementsCaptionsLineItems_5c53b79e-cd18-4d84-b845-68d2e0c0a018" xlink:to="loc_us-gaap_LiabilitiesAbstract_44973fc9-71f2-4c73-b3fc-bfca3f5be670" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockValue_ee3eccc0-9dd9-4e02-9e18-7cca8894ceac" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PreferredStockValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_44973fc9-71f2-4c73-b3fc-bfca3f5be670" xlink:to="loc_us-gaap_PreferredStockValue_ee3eccc0-9dd9-4e02-9e18-7cca8894ceac" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockValue_eee9fd4c-df95-4dc0-ba03-cee1eddfa4ad" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CommonStockValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_44973fc9-71f2-4c73-b3fc-bfca3f5be670" xlink:to="loc_us-gaap_CommonStockValue_eee9fd4c-df95-4dc0-ba03-cee1eddfa4ad" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapital_1d70dd01-129f-4fd3-8012-496fc21d287b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AdditionalPaidInCapital"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_44973fc9-71f2-4c73-b3fc-bfca3f5be670" xlink:to="loc_us-gaap_AdditionalPaidInCapital_1d70dd01-129f-4fd3-8012-496fc21d287b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_4ab2103d-a7b0-4ab7-85c8-507bcaa986b3" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_44973fc9-71f2-4c73-b3fc-bfca3f5be670" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_4ab2103d-a7b0-4ab7-85c8-507bcaa986b3" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_3071dd40-300e-4139-8131-150f17bad4ac" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetainedEarningsAccumulatedDeficit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_44973fc9-71f2-4c73-b3fc-bfca3f5be670" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_3071dd40-300e-4139-8131-150f17bad4ac" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_7fa7e42b-9a4c-4719-8e72-d22e51104b72" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_44973fc9-71f2-4c73-b3fc-bfca3f5be670" xlink:to="loc_us-gaap_StockholdersEquity_7fa7e42b-9a4c-4719-8e72-d22e51104b72" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_cabc170e-1248-4a08-9b67-4572410548f8" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_44973fc9-71f2-4c73-b3fc-bfca3f5be670" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquity_cabc170e-1248-4a08-9b67-4572410548f8" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockParOrStatedValuePerShare_d99c7c8c-9b71-41e0-8866-9b579a5e0cf4" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PreferredStockParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_44973fc9-71f2-4c73-b3fc-bfca3f5be670" xlink:to="loc_us-gaap_PreferredStockParOrStatedValuePerShare_d99c7c8c-9b71-41e0-8866-9b579a5e0cf4" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesAuthorized_a5d1b59a-8a76-4829-829d-56a95dfda475" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PreferredStockSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_44973fc9-71f2-4c73-b3fc-bfca3f5be670" xlink:to="loc_us-gaap_PreferredStockSharesAuthorized_a5d1b59a-8a76-4829-829d-56a95dfda475" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesIssued_c2bcdf11-2e16-40f3-9de8-084a984b075e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PreferredStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_44973fc9-71f2-4c73-b3fc-bfca3f5be670" xlink:to="loc_us-gaap_PreferredStockSharesIssued_c2bcdf11-2e16-40f3-9de8-084a984b075e" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesOutstanding_3c2da4d8-c465-4184-a866-17de01ee5e9d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PreferredStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_44973fc9-71f2-4c73-b3fc-bfca3f5be670" xlink:to="loc_us-gaap_PreferredStockSharesOutstanding_3c2da4d8-c465-4184-a866-17de01ee5e9d" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockParOrStatedValuePerShare_b5364bc1-521d-4a91-9a99-123bfecfbf1e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CommonStockParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_44973fc9-71f2-4c73-b3fc-bfca3f5be670" xlink:to="loc_us-gaap_CommonStockParOrStatedValuePerShare_b5364bc1-521d-4a91-9a99-123bfecfbf1e" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesAuthorized_52ab7c8b-ddf7-4dfe-aa4d-8d5477112159" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CommonStockSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_44973fc9-71f2-4c73-b3fc-bfca3f5be670" xlink:to="loc_us-gaap_CommonStockSharesAuthorized_52ab7c8b-ddf7-4dfe-aa4d-8d5477112159" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesIssued_18327047-1f23-4207-b2a4-04c96a411984" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CommonStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_44973fc9-71f2-4c73-b3fc-bfca3f5be670" xlink:to="loc_us-gaap_CommonStockSharesIssued_18327047-1f23-4207-b2a4-04c96a411984" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_6fefc381-f345-455c-8b29-d0eb9fbc5198" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_44973fc9-71f2-4c73-b3fc-bfca3f5be670" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_6fefc381-f345-455c-8b29-d0eb9fbc5198" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CondensedBalanceSheetStatementTable_2ad7db10-a6aa-450f-8920-d6c9647796d0" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_CondensedBalanceSheetStatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_srt_CondensedBalanceSheetStatementsCaptionsLineItems_5c53b79e-cd18-4d84-b845-68d2e0c0a018" xlink:to="loc_srt_CondensedBalanceSheetStatementTable_2ad7db10-a6aa-450f-8920-d6c9647796d0" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_fd559f50-62bb-476f-b51c-b967404e127e" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ConsolidatedEntitiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_srt_CondensedBalanceSheetStatementTable_2ad7db10-a6aa-450f-8920-d6c9647796d0" xlink:to="loc_srt_ConsolidatedEntitiesAxis_fd559f50-62bb-476f-b51c-b967404e127e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_fd559f50-62bb-476f-b51c-b967404e127e_default" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_fd559f50-62bb-476f-b51c-b967404e127e" xlink:to="loc_srt_ConsolidatedEntitiesDomain_fd559f50-62bb-476f-b51c-b967404e127e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_026d8aed-4f3e-4499-ab94-24b49a65e3af" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_fd559f50-62bb-476f-b51c-b967404e127e" xlink:to="loc_srt_ConsolidatedEntitiesDomain_026d8aed-4f3e-4499-ab94-24b49a65e3af" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ParentCompanyMember_154ba6e0-047e-4f4d-9e46-627fcd058c2b" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ParentCompanyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_026d8aed-4f3e-4499-ab94-24b49a65e3af" xlink:to="loc_srt_ParentCompanyMember_154ba6e0-047e-4f4d-9e46-627fcd058c2b" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.rackspace.com/role/CondensedFinancialInformationofRegistrantParentCompanyOnlyCondensedStatementsofComprehensiveLossDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#CondensedFinancialInformationofRegistrantParentCompanyOnlyCondensedStatementsofComprehensiveLossDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/CondensedFinancialInformationofRegistrantParentCompanyOnlyCondensedStatementsofComprehensiveLossDetails" xlink:type="extended" id="i2cfbb8d628744fef8fd2f4ede31fdc05_CondensedFinancialInformationofRegistrantParentCompanyOnlyCondensedStatementsofComprehensiveLossDetails">
    <link:loc xlink:type="locator" xlink:label="loc_srt_CondensedStatementOfIncomeCaptionsLineItems_48232810-6fa4-4c69-ae59-ddceb764379a" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_CondensedStatementOfIncomeCaptionsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_e149792b-37f8-449f-81d5-9bd282eef3ed" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_CondensedStatementOfIncomeCaptionsLineItems_48232810-6fa4-4c69-ae59-ddceb764379a" xlink:to="loc_us-gaap_NetIncomeLoss_e149792b-37f8-449f-81d5-9bd282eef3ed" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasicAndDiluted_29d66372-51a0-477f-a8f3-8a2e261a33ea" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EarningsPerShareBasicAndDiluted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_CondensedStatementOfIncomeCaptionsLineItems_48232810-6fa4-4c69-ae59-ddceb764379a" xlink:to="loc_us-gaap_EarningsPerShareBasicAndDiluted_29d66372-51a0-477f-a8f3-8a2e261a33ea" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted_d9b0d0e5-5008-4112-84ed-715353dc92f3" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_CondensedStatementOfIncomeCaptionsLineItems_48232810-6fa4-4c69-ae59-ddceb764379a" xlink:to="loc_us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted_d9b0d0e5-5008-4112-84ed-715353dc92f3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CondensedStatementOfComprehensiveIncomeTable_88123d73-6972-4ff1-bf34-d8955b0e8485" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_CondensedStatementOfComprehensiveIncomeTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_srt_CondensedStatementOfIncomeCaptionsLineItems_48232810-6fa4-4c69-ae59-ddceb764379a" xlink:to="loc_srt_CondensedStatementOfComprehensiveIncomeTable_88123d73-6972-4ff1-bf34-d8955b0e8485" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_e21a2aee-6ba8-471b-b79f-38c1ef2fd444" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ConsolidatedEntitiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_srt_CondensedStatementOfComprehensiveIncomeTable_88123d73-6972-4ff1-bf34-d8955b0e8485" xlink:to="loc_srt_ConsolidatedEntitiesAxis_e21a2aee-6ba8-471b-b79f-38c1ef2fd444" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_e21a2aee-6ba8-471b-b79f-38c1ef2fd444_default" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_e21a2aee-6ba8-471b-b79f-38c1ef2fd444" xlink:to="loc_srt_ConsolidatedEntitiesDomain_e21a2aee-6ba8-471b-b79f-38c1ef2fd444_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_30635e99-69c6-4259-87c7-fd5f0084b4c5" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_e21a2aee-6ba8-471b-b79f-38c1ef2fd444" xlink:to="loc_srt_ConsolidatedEntitiesDomain_30635e99-69c6-4259-87c7-fd5f0084b4c5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ParentCompanyMember_32a89b76-2516-4da9-aecb-b74c9c13f39f" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ParentCompanyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_30635e99-69c6-4259-87c7-fd5f0084b4c5" xlink:to="loc_srt_ParentCompanyMember_32a89b76-2516-4da9-aecb-b74c9c13f39f" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.rackspace.com/role/CondensedFinancialInformationofRegistrantParentCompanyOnlyDetails" xlink:type="simple" xlink:href="rxt-20201231.xsd#CondensedFinancialInformationofRegistrantParentCompanyOnlyDetails"/>
  <link:definitionLink xlink:role="http://www.rackspace.com/role/CondensedFinancialInformationofRegistrantParentCompanyOnlyDetails" xlink:type="extended" id="i769d6c98e96c4c39b663f72704122a4d_CondensedFinancialInformationofRegistrantParentCompanyOnlyDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_c095096c-73ff-4456-b3f6-881b5e635ce6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_d6c243c4-9413-4e3d-9497-bd8f07a6a3c7" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c095096c-73ff-4456-b3f6-881b5e635ce6" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_d6c243c4-9413-4e3d-9497-bd8f07a6a3c7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_d8fe8ce6-dc16-4616-9050-52a4145497a6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c095096c-73ff-4456-b3f6-881b5e635ce6" xlink:to="loc_us-gaap_DebtInstrumentTable_d8fe8ce6-dc16-4616-9050-52a4145497a6" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_57df9202-9f9b-4790-8498-880a46f3d93f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_d8fe8ce6-dc16-4616-9050-52a4145497a6" xlink:to="loc_us-gaap_DebtInstrumentAxis_57df9202-9f9b-4790-8498-880a46f3d93f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_57df9202-9f9b-4790-8498-880a46f3d93f_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_57df9202-9f9b-4790-8498-880a46f3d93f" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_57df9202-9f9b-4790-8498-880a46f3d93f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_c1613108-4c48-4eb5-8783-91826747abd9" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_57df9202-9f9b-4790-8498-880a46f3d93f" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_c1613108-4c48-4eb5-8783-91826747abd9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rxt_SeniorNotes5375Due2028Member_96def7ea-e262-40c1-a963-8ec962c6c3b2" xlink:href="rxt-20201231.xsd#rxt_SeniorNotes5375Due2028Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_c1613108-4c48-4eb5-8783-91826747abd9" xlink:to="loc_rxt_SeniorNotes5375Due2028Member_96def7ea-e262-40c1-a963-8ec962c6c3b2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_29aaf03c-2368-4e15-9bd2-c83da5fb3935" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_d8fe8ce6-dc16-4616-9050-52a4145497a6" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_29aaf03c-2368-4e15-9bd2-c83da5fb3935" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_29aaf03c-2368-4e15-9bd2-c83da5fb3935_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_29aaf03c-2368-4e15-9bd2-c83da5fb3935" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_29aaf03c-2368-4e15-9bd2-c83da5fb3935_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_2d0040c8-c621-4367-8a07-66d3a48efe4e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_29aaf03c-2368-4e15-9bd2-c83da5fb3935" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_2d0040c8-c621-4367-8a07-66d3a48efe4e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorNotesMember_4d1e6475-b9c5-4f01-afe9-16abba34d983" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_2d0040c8-c621-4367-8a07-66d3a48efe4e" xlink:to="loc_us-gaap_SeniorNotesMember_4d1e6475-b9c5-4f01-afe9-16abba34d983" xlink:type="arc" order="0"/>
  </link:definitionLink>
</link:linkbase>
