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

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:019ff0f8-75ff-7105-a413-f0370e54346c,g:c35f27c3-c105-44b4-b2c1-e9e6ec7880d5-->
<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.dynatrace.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFOPERATIONS" xlink:type="simple" xlink:href="dt-20260930.xsd#CONDENSEDCONSOLIDATEDSTATEMENTSOFOPERATIONS"/>
  <link:definitionLink xlink:role="http://www.dynatrace.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFOPERATIONS" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_019ff0f8-76bf-7052-8b4b-613571b08a8d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_019ff0f8-76bf-7b40-8412-8df23f9fc5c8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_019ff0f8-76bf-7052-8b4b-613571b08a8d" xlink:to="loc_us-gaap_StatementTable_019ff0f8-76bf-7b40-8412-8df23f9fc5c8" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_019ff0f8-76bf-7b98-a534-ec9cf5d2383d" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019ff0f8-76bf-7b40-8412-8df23f9fc5c8" xlink:to="loc_srt_ProductOrServiceAxis_019ff0f8-76bf-7b98-a534-ec9cf5d2383d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019ff0f8-76bf-7b98-a534-ec9cf5d2383d_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_019ff0f8-76bf-7b98-a534-ec9cf5d2383d" xlink:to="loc_srt_ProductsAndServicesDomain_019ff0f8-76bf-7b98-a534-ec9cf5d2383d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019ff0f8-76bf-7dda-b6eb-d4ea0c2ebf12" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_019ff0f8-76bf-7b98-a534-ec9cf5d2383d" xlink:to="loc_srt_ProductsAndServicesDomain_019ff0f8-76bf-7dda-b6eb-d4ea0c2ebf12" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubscriptionAndCirculationMember_019ff0f8-76bf-732f-9a35-2d36bda58583" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubscriptionAndCirculationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019ff0f8-76bf-7dda-b6eb-d4ea0c2ebf12" xlink:to="loc_us-gaap_SubscriptionAndCirculationMember_019ff0f8-76bf-732f-9a35-2d36bda58583" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ServiceMember_019ff0f8-76bf-71ca-bab5-cb1f1874f397" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ServiceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019ff0f8-76bf-7dda-b6eb-d4ea0c2ebf12" xlink:to="loc_us-gaap_ServiceMember_019ff0f8-76bf-71ca-bab5-cb1f1874f397" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerAbstract_019ff0f8-76bf-7229-b6b8-b5b8d3dc5a63" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueFromContractWithCustomerAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ff0f8-76bf-7052-8b4b-613571b08a8d" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerAbstract_019ff0f8-76bf-7229-b6b8-b5b8d3dc5a63" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019ff0f8-76bf-7d6c-b796-4aad83eb86e8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueFromContractWithCustomerAbstract_019ff0f8-76bf-7229-b6b8-b5b8d3dc5a63" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019ff0f8-76bf-7d6c-b796-4aad83eb86e8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfRevenueAbstract_019ff0f8-76bf-73c7-b77c-c8e31b37dd81" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CostOfRevenueAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ff0f8-76bf-7052-8b4b-613571b08a8d" xlink:to="loc_us-gaap_CostOfRevenueAbstract_019ff0f8-76bf-73c7-b77c-c8e31b37dd81" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfGoodsAndServiceExcludingDepreciationDepletionAndAmortization_019ff0f8-76bf-7bcc-860f-2dc5e06eeb5c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CostOfGoodsAndServiceExcludingDepreciationDepletionAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostOfRevenueAbstract_019ff0f8-76bf-73c7-b77c-c8e31b37dd81" xlink:to="loc_us-gaap_CostOfGoodsAndServiceExcludingDepreciationDepletionAndAmortization_019ff0f8-76bf-7bcc-860f-2dc5e06eeb5c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfGoodsAndServicesSoldAmortization_019ff0f8-76bf-72e0-8f37-db698095545d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CostOfGoodsAndServicesSoldAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostOfRevenueAbstract_019ff0f8-76bf-73c7-b77c-c8e31b37dd81" xlink:to="loc_us-gaap_CostOfGoodsAndServicesSoldAmortization_019ff0f8-76bf-72e0-8f37-db698095545d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfGoodsAndServicesSold_019ff0f8-76bf-74eb-80d6-9e024013dc7c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CostOfGoodsAndServicesSold"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostOfRevenueAbstract_019ff0f8-76bf-73c7-b77c-c8e31b37dd81" xlink:to="loc_us-gaap_CostOfGoodsAndServicesSold_019ff0f8-76bf-74eb-80d6-9e024013dc7c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GrossProfit_019ff0f8-76bf-77ae-9be2-7698727e4802" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GrossProfit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ff0f8-76bf-7052-8b4b-613571b08a8d" xlink:to="loc_us-gaap_GrossProfit_019ff0f8-76bf-77ae-9be2-7698727e4802" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpensesAbstract_019ff0f8-76bf-7845-b88d-d7ed5cbb7263" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingExpensesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ff0f8-76bf-7052-8b4b-613571b08a8d" xlink:to="loc_us-gaap_OperatingExpensesAbstract_019ff0f8-76bf-7845-b88d-d7ed5cbb7263" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpense_019ff0f8-76bf-78de-b76a-e1901d705168" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ResearchAndDevelopmentExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_019ff0f8-76bf-7845-b88d-d7ed5cbb7263" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpense_019ff0f8-76bf-78de-b76a-e1901d705168" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingAndMarketingExpense_019ff0f8-76bf-7b97-aa4f-c5aa3bbdce08" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SellingAndMarketingExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_019ff0f8-76bf-7845-b88d-d7ed5cbb7263" xlink:to="loc_us-gaap_SellingAndMarketingExpense_019ff0f8-76bf-7b97-aa4f-c5aa3bbdce08" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpense_019ff0f8-76bf-7845-95b0-fdadc7cdc960" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GeneralAndAdministrativeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_019ff0f8-76bf-7845-b88d-d7ed5cbb7263" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpense_019ff0f8-76bf-7845-95b0-fdadc7cdc960" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_AmortizationOfOtherIntangibleAssets_019ff0f8-76bf-7bbe-ba30-8cdfae941242" xlink:href="dt-20260930.xsd#dt_AmortizationOfOtherIntangibleAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_019ff0f8-76bf-7845-b88d-d7ed5cbb7263" xlink:to="loc_dt_AmortizationOfOtherIntangibleAssets_019ff0f8-76bf-7bbe-ba30-8cdfae941242" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpenses_019ff0f8-76bf-7590-b0df-5cec375a3722" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingExpenses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_019ff0f8-76bf-7845-b88d-d7ed5cbb7263" xlink:to="loc_us-gaap_OperatingExpenses_019ff0f8-76bf-7590-b0df-5cec375a3722" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_019ff0f8-76bf-7277-a935-819657b14309" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ff0f8-76bf-7052-8b4b-613571b08a8d" xlink:to="loc_us-gaap_OperatingIncomeLoss_019ff0f8-76bf-7277-a935-819657b14309" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeExpenseNonoperatingNet_019ff0f8-76bf-7e5c-88e7-f6d5c4a48db3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestIncomeExpenseNonoperatingNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ff0f8-76bf-7052-8b4b-613571b08a8d" xlink:to="loc_us-gaap_InterestIncomeExpenseNonoperatingNet_019ff0f8-76bf-7e5c-88e7-f6d5c4a48db3" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_019ff0f8-76bf-743e-860b-f3a25f3aec8d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherNonoperatingIncomeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ff0f8-76bf-7052-8b4b-613571b08a8d" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_019ff0f8-76bf-743e-860b-f3a25f3aec8d" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019ff0f8-76bf-7c57-8648-2bf892206016" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ff0f8-76bf-7052-8b4b-613571b08a8d" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019ff0f8-76bf-7c57-8648-2bf892206016" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_019ff0f8-76bf-788b-bba1-69c0a10bc8c1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ff0f8-76bf-7052-8b4b-613571b08a8d" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_019ff0f8-76bf-788b-bba1-69c0a10bc8c1" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019ff0f8-76bf-7076-b432-ceeeb9263da6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ff0f8-76bf-7052-8b4b-613571b08a8d" xlink:to="loc_us-gaap_NetIncomeLoss_019ff0f8-76bf-7076-b432-ceeeb9263da6" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareAbstract_019ff0f8-76bf-7c99-9211-9df0562e21f9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ff0f8-76bf-7052-8b4b-613571b08a8d" xlink:to="loc_us-gaap_EarningsPerShareAbstract_019ff0f8-76bf-7c99-9211-9df0562e21f9" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasic_019ff0f8-76bf-7de2-a810-105eb7eb3bc2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareAbstract_019ff0f8-76bf-7c99-9211-9df0562e21f9" xlink:to="loc_us-gaap_EarningsPerShareBasic_019ff0f8-76bf-7de2-a810-105eb7eb3bc2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareDiluted_019ff0f8-76bf-7625-b3d5-a5f377f30828" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareDiluted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareAbstract_019ff0f8-76bf-7c99-9211-9df0562e21f9" xlink:to="loc_us-gaap_EarningsPerShareDiluted_019ff0f8-76bf-7625-b3d5-a5f377f30828" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingDilutedDisclosureItemsAbstract_019ff0f8-76bf-79da-a380-644f372c6205" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingDilutedDisclosureItemsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ff0f8-76bf-7052-8b4b-613571b08a8d" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingDilutedDisclosureItemsAbstract_019ff0f8-76bf-79da-a380-644f372c6205" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_019ff0f8-76bf-7bc0-834f-41bb3efa137d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingDilutedDisclosureItemsAbstract_019ff0f8-76bf-79da-a380-644f372c6205" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_019ff0f8-76bf-7bc0-834f-41bb3efa137d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_019ff0f8-76bf-73be-8ad9-078d905b191d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingDilutedDisclosureItemsAbstract_019ff0f8-76bf-79da-a380-644f372c6205" xlink:to="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_019ff0f8-76bf-73be-8ad9-078d905b191d" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.dynatrace.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFSHAREHOLDERSEQUITY" xlink:type="simple" xlink:href="dt-20260930.xsd#CONDENSEDCONSOLIDATEDSTATEMENTSOFSHAREHOLDERSEQUITY"/>
  <link:definitionLink xlink:role="http://www.dynatrace.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFSHAREHOLDERSEQUITY" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_019ff0f8-76bf-7145-b744-956a4a9439c7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_019ff0f8-76bf-7251-90cc-6640f6bc4ae8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_019ff0f8-76bf-7145-b744-956a4a9439c7" xlink:to="loc_us-gaap_StatementTable_019ff0f8-76bf-7251-90cc-6640f6bc4ae8" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_019ff0f8-76bf-7b7b-8618-067d9f1c09db" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019ff0f8-76bf-7251-90cc-6640f6bc4ae8" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_019ff0f8-76bf-7b7b-8618-067d9f1c09db" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019ff0f8-76bf-7b7b-8618-067d9f1c09db_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019ff0f8-76bf-7b7b-8618-067d9f1c09db" xlink:to="loc_us-gaap_EquityComponentDomain_019ff0f8-76bf-7b7b-8618-067d9f1c09db_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019ff0f8-76bf-75a6-be88-c34b2518e6bd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019ff0f8-76bf-7b7b-8618-067d9f1c09db" xlink:to="loc_us-gaap_EquityComponentDomain_019ff0f8-76bf-75a6-be88-c34b2518e6bd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_019ff0f8-76bf-7d66-b739-fc8afab944e2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019ff0f8-76bf-75a6-be88-c34b2518e6bd" xlink:to="loc_us-gaap_CommonStockMember_019ff0f8-76bf-7d66-b739-fc8afab944e2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_019ff0f8-76bf-7433-985d-fd984387b55a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019ff0f8-76bf-75a6-be88-c34b2518e6bd" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_019ff0f8-76bf-7433-985d-fd984387b55a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_019ff0f8-76bf-7b9c-9f43-f626705710fc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RetainedEarningsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019ff0f8-76bf-75a6-be88-c34b2518e6bd" xlink:to="loc_us-gaap_RetainedEarningsMember_019ff0f8-76bf-7b9c-9f43-f626705710fc" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019ff0f8-76bf-7acc-92ad-93061a570cb0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019ff0f8-76bf-75a6-be88-c34b2518e6bd" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019ff0f8-76bf-7acc-92ad-93061a570cb0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019ff0f8-76bf-791a-80d8-c51ec359bc34" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ff0f8-76bf-7145-b744-956a4a9439c7" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019ff0f8-76bf-791a-80d8-c51ec359bc34" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_019ff0f8-76bf-7f31-a93d-aa8f2163128a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019ff0f8-76bf-791a-80d8-c51ec359bc34" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_019ff0f8-76bf-7f31-a93d-aa8f2163128a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019ff0f8-76bf-7429-ade3-caaea52ee1d5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019ff0f8-76bf-791a-80d8-c51ec359bc34" xlink:to="loc_us-gaap_StockholdersEquity_019ff0f8-76bf-7429-ade3-caaea52ee1d5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_019ff0f8-76bf-7941-b537-5e8c6b3f8375" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019ff0f8-76bf-791a-80d8-c51ec359bc34" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_019ff0f8-76bf-7941-b537-5e8c6b3f8375" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_AdjustmentsToAdditionalPaidInCapitalPurchaseOfExchangeableNoteHedge_01a14401-a6fe-7757-9058-e4015ba1f486" xlink:href="dt-20260930.xsd#dt_AdjustmentsToAdditionalPaidInCapitalPurchaseOfExchangeableNoteHedge"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019ff0f8-76bf-791a-80d8-c51ec359bc34" xlink:to="loc_dt_AdjustmentsToAdditionalPaidInCapitalPurchaseOfExchangeableNoteHedge_01a14401-a6fe-7757-9058-e4015ba1f486" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalWarrantIssued_01a0f53c-b841-7da3-974b-8096d97047e1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalWarrantIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019ff0f8-76bf-791a-80d8-c51ec359bc34" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalWarrantIssued_01a0f53c-b841-7da3-974b-8096d97047e1" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures_019ff0f8-76bf-7f33-990c-2b4c4de33f37" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019ff0f8-76bf-791a-80d8-c51ec359bc34" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures_019ff0f8-76bf-7f33-990c-2b4c4de33f37" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures_019ff0f8-76bf-7805-924d-a66c21430a7d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019ff0f8-76bf-791a-80d8-c51ec359bc34" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures_019ff0f8-76bf-7805-924d-a66c21430a7d" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardGross_019ff0f8-76bf-706a-94db-9edfc57f09c4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019ff0f8-76bf-791a-80d8-c51ec359bc34" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardGross_019ff0f8-76bf-706a-94db-9edfc57f09c4" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans_019ff0f8-76bf-7f78-9183-3f01cf0df237" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019ff0f8-76bf-791a-80d8-c51ec359bc34" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans_019ff0f8-76bf-7f78-9183-3f01cf0df237" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueEmployeeStockPurchasePlan_019ff0f8-76bf-78bd-ae31-91ac9ba796c9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodValueEmployeeStockPurchasePlan"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019ff0f8-76bf-791a-80d8-c51ec359bc34" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueEmployeeStockPurchasePlan_019ff0f8-76bf-78bd-ae31-91ac9ba796c9" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_019ff0f8-76bf-75b8-bc9b-dc0faf56e8df" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019ff0f8-76bf-791a-80d8-c51ec359bc34" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_019ff0f8-76bf-75b8-bc9b-dc0faf56e8df" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised_019ff0f8-76bf-7a97-b443-e479fdc5448d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019ff0f8-76bf-791a-80d8-c51ec359bc34" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised_019ff0f8-76bf-7a97-b443-e479fdc5448d" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_019ff0f8-76bf-713c-bdb0-9148f857cf79" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019ff0f8-76bf-791a-80d8-c51ec359bc34" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_019ff0f8-76bf-713c-bdb0-9148f857cf79" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation_019ff0f8-76bf-77a2-8be1-bb2045002460" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019ff0f8-76bf-791a-80d8-c51ec359bc34" xlink:to="loc_us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation_019ff0f8-76bf-77a2-8be1-bb2045002460" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation_019ff0f8-76bf-7721-9e7f-35a53e3d1536" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019ff0f8-76bf-791a-80d8-c51ec359bc34" xlink:to="loc_us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation_019ff0f8-76bf-7721-9e7f-35a53e3d1536" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodShares_019ff0f8-76bf-703b-b369-cb9b2e741275" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockRepurchasedDuringPeriodShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019ff0f8-76bf-791a-80d8-c51ec359bc34" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodShares_019ff0f8-76bf-703b-b369-cb9b2e741275" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodValue_019ff0f8-76bf-7714-a102-70d211710149" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockRepurchasedDuringPeriodValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019ff0f8-76bf-791a-80d8-c51ec359bc34" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodValue_019ff0f8-76bf-7714-a102-70d211710149" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019ff0f8-76bf-7aa8-aff3-41d354d56ecf" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019ff0f8-76bf-791a-80d8-c51ec359bc34" xlink:to="loc_us-gaap_NetIncomeLoss_019ff0f8-76bf-7aa8-aff3-41d354d56ecf" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_019ff0f8-76bf-74b8-a48b-24cda81c1494" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019ff0f8-76bf-7d12-b03c-7600cc93ab69" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.dynatrace.com/role/RevenueRecognitionScheduleofRevenuebyGeographicRegionDetails" xlink:type="simple" xlink:href="dt-20260930.xsd#RevenueRecognitionScheduleofRevenuebyGeographicRegionDetails"/>
  <link:definitionLink xlink:role="http://www.dynatrace.com/role/RevenueRecognitionScheduleofRevenuebyGeographicRegionDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_019ff0f8-776b-7aa9-bf97-26e6982a763e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisaggregationOfRevenueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_019ff0f8-776b-7c76-8e93-45a54dacf9d4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisaggregationOfRevenueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019ff0f8-776b-7aa9-bf97-26e6982a763e" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_019ff0f8-776b-7c76-8e93-45a54dacf9d4" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_019ff0f8-776b-7bf4-b6d1-56d2c9bd57b8" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019ff0f8-776b-7c76-8e93-45a54dacf9d4" xlink:to="loc_srt_StatementGeographicalAxis_019ff0f8-776b-7bf4-b6d1-56d2c9bd57b8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_019ff0f8-776b-7bf4-b6d1-56d2c9bd57b8_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_019ff0f8-776b-7bf4-b6d1-56d2c9bd57b8" xlink:to="loc_srt_SegmentGeographicalDomain_019ff0f8-776b-7bf4-b6d1-56d2c9bd57b8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_019ff0f8-776b-7c5f-8821-0b2bc7e803f3" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_019ff0f8-776b-7bf4-b6d1-56d2c9bd57b8" xlink:to="loc_srt_SegmentGeographicalDomain_019ff0f8-776b-7c5f-8821-0b2bc7e803f3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NorthAmericaMember_019ff0f8-776b-7a5a-ba83-2b98122c1bd9" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_NorthAmericaMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019ff0f8-776b-7c5f-8821-0b2bc7e803f3" xlink:to="loc_srt_NorthAmericaMember_019ff0f8-776b-7a5a-ba83-2b98122c1bd9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EMEAMember_019ff0f8-776b-73de-a953-5b496943c94f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EMEAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019ff0f8-776b-7c5f-8821-0b2bc7e803f3" xlink:to="loc_us-gaap_EMEAMember_019ff0f8-776b-73de-a953-5b496943c94f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AsiaPacificMember_019ff0f8-776b-7436-a704-fede2e4f93ce" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_AsiaPacificMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019ff0f8-776b-7c5f-8821-0b2bc7e803f3" xlink:to="loc_srt_AsiaPacificMember_019ff0f8-776b-7436-a704-fede2e4f93ce" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_LatinAmericaMember_019ff0f8-776b-7aed-a73e-07c8313531c8" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_LatinAmericaMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019ff0f8-776b-7c5f-8821-0b2bc7e803f3" xlink:to="loc_srt_LatinAmericaMember_019ff0f8-776b-7aed-a73e-07c8313531c8" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019ff0f8-776b-7587-b76a-68ea3bd375d8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019ff0f8-776b-7c76-8e93-45a54dacf9d4" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019ff0f8-776b-7587-b76a-68ea3bd375d8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019ff0f8-776b-7587-b76a-68ea3bd375d8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019ff0f8-776b-7587-b76a-68ea3bd375d8" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019ff0f8-776b-7587-b76a-68ea3bd375d8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019ff0f8-776b-79cd-9179-c08c19ae9aad" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019ff0f8-776b-7587-b76a-68ea3bd375d8" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019ff0f8-776b-79cd-9179-c08c19ae9aad" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerMember_019ff0f8-776b-7296-a490-49ed77c25520" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueFromContractWithCustomerMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019ff0f8-776b-79cd-9179-c08c19ae9aad" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerMember_019ff0f8-776b-7296-a490-49ed77c25520" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_019ff0f8-776b-77e2-a736-e569ae902959" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConcentrationRiskByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019ff0f8-776b-7c76-8e93-45a54dacf9d4" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_019ff0f8-776b-77e2-a736-e569ae902959" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_019ff0f8-776b-77e2-a736-e569ae902959_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_019ff0f8-776b-77e2-a736-e569ae902959" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_019ff0f8-776b-77e2-a736-e569ae902959_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_019ff0f8-776b-77c6-a88c-96392b0eb580" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_019ff0f8-776b-77e2-a736-e569ae902959" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_019ff0f8-776b-77c6-a88c-96392b0eb580" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeographicConcentrationRiskMember_019ff0f8-776b-763e-a372-460ac8ed401a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GeographicConcentrationRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_019ff0f8-776b-77c6-a88c-96392b0eb580" xlink:to="loc_us-gaap_GeographicConcentrationRiskMember_019ff0f8-776b-763e-a372-460ac8ed401a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019ff0f8-776b-7c29-82d7-b3c0aaf3ef79" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019ff0f8-776b-7aa9-bf97-26e6982a763e" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019ff0f8-776b-7c29-82d7-b3c0aaf3ef79" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1_019ff0f8-776b-71e8-9eb5-aca273f812f3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConcentrationRiskPercentage1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019ff0f8-776b-7aa9-bf97-26e6982a763e" xlink:to="loc_us-gaap_ConcentrationRiskPercentage1_019ff0f8-776b-71e8-9eb5-aca273f812f3" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.dynatrace.com/role/RevenueRecognitionNarrativeDetails" xlink:type="simple" xlink:href="dt-20260930.xsd#RevenueRecognitionNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.dynatrace.com/role/RevenueRecognitionNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_019ff0f8-776b-70bc-90cd-f96a9eb4632b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisaggregationOfRevenueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_019ff0f8-776b-7dcc-b63d-55b34af95b0f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisaggregationOfRevenueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019ff0f8-776b-70bc-90cd-f96a9eb4632b" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_019ff0f8-776b-7dcc-b63d-55b34af95b0f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019ff0f8-776b-7060-bfda-2a1062031ed6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019ff0f8-776b-7dcc-b63d-55b34af95b0f" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019ff0f8-776b-7060-bfda-2a1062031ed6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019ff0f8-776b-7060-bfda-2a1062031ed6_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019ff0f8-776b-7060-bfda-2a1062031ed6" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019ff0f8-776b-7060-bfda-2a1062031ed6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019ff0f8-776b-7699-a5a7-a20dd311b9af" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019ff0f8-776b-7060-bfda-2a1062031ed6" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019ff0f8-776b-7699-a5a7-a20dd311b9af" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerMember_019ff0f8-776b-7623-9c06-3590819c782c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueFromContractWithCustomerMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019ff0f8-776b-7699-a5a7-a20dd311b9af" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerMember_019ff0f8-776b-7623-9c06-3590819c782c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_019ff0f8-776b-7bfa-8c24-119afdafb639" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConcentrationRiskByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019ff0f8-776b-7dcc-b63d-55b34af95b0f" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_019ff0f8-776b-7bfa-8c24-119afdafb639" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_019ff0f8-776b-7bfa-8c24-119afdafb639_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_019ff0f8-776b-7bfa-8c24-119afdafb639" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_019ff0f8-776b-7bfa-8c24-119afdafb639_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_019ff0f8-776b-75e3-ba6f-f42babf956ad" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_019ff0f8-776b-7bfa-8c24-119afdafb639" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_019ff0f8-776b-75e3-ba6f-f42babf956ad" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeographicConcentrationRiskMember_019ff0f8-776b-7bfc-a700-7e0239562cf3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GeographicConcentrationRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_019ff0f8-776b-75e3-ba6f-f42babf956ad" xlink:to="loc_us-gaap_GeographicConcentrationRiskMember_019ff0f8-776b-7bfc-a700-7e0239562cf3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_019ff0f8-776b-701d-be1c-cfcade455e20" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019ff0f8-776b-7dcc-b63d-55b34af95b0f" xlink:to="loc_srt_StatementGeographicalAxis_019ff0f8-776b-701d-be1c-cfcade455e20" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_019ff0f8-776b-701d-be1c-cfcade455e20_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_019ff0f8-776b-701d-be1c-cfcade455e20" xlink:to="loc_srt_SegmentGeographicalDomain_019ff0f8-776b-701d-be1c-cfcade455e20_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_019ff0f8-776b-7835-a960-ab7a3e133dee" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_019ff0f8-776b-701d-be1c-cfcade455e20" xlink:to="loc_srt_SegmentGeographicalDomain_019ff0f8-776b-7835-a960-ab7a3e133dee" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_019ff0f8-776b-7fd4-a8e4-a9031899bb17" xlink:href="https://xbrl.sec.gov/country/2026/country-2026.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019ff0f8-776b-7835-a960-ab7a3e133dee" xlink:to="loc_country_US_019ff0f8-776b-7fd4-a8e4-a9031899bb17" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsNotesLoansAndFinancingReceivablesByBillingStatusTypeAxis_019ff0f8-776b-7ac8-b616-5a7208d7f7d3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsNotesLoansAndFinancingReceivablesByBillingStatusTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019ff0f8-776b-7dcc-b63d-55b34af95b0f" xlink:to="loc_us-gaap_AccountsNotesLoansAndFinancingReceivablesByBillingStatusTypeAxis_019ff0f8-776b-7ac8-b616-5a7208d7f7d3" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReceivablesBillingStatusDomain_019ff0f8-776b-7ac8-b616-5a7208d7f7d3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReceivablesBillingStatusDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AccountsNotesLoansAndFinancingReceivablesByBillingStatusTypeAxis_019ff0f8-776b-7ac8-b616-5a7208d7f7d3" xlink:to="loc_us-gaap_ReceivablesBillingStatusDomain_019ff0f8-776b-7ac8-b616-5a7208d7f7d3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReceivablesBillingStatusDomain_019ff0f8-776b-7d7d-9517-aa618d0a079d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReceivablesBillingStatusDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AccountsNotesLoansAndFinancingReceivablesByBillingStatusTypeAxis_019ff0f8-776b-7ac8-b616-5a7208d7f7d3" xlink:to="loc_us-gaap_ReceivablesBillingStatusDomain_019ff0f8-776b-7d7d-9517-aa618d0a079d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BilledRevenuesMember_019ff0f8-776b-7b42-9eae-a20178282999" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BilledRevenuesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReceivablesBillingStatusDomain_019ff0f8-776b-7d7d-9517-aa618d0a079d" xlink:to="loc_us-gaap_BilledRevenuesMember_019ff0f8-776b-7b42-9eae-a20178282999" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnbilledRevenuesMember_019ff0f8-776b-7c5d-a2b1-3de5a72dfa36" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_UnbilledRevenuesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReceivablesBillingStatusDomain_019ff0f8-776b-7d7d-9517-aa618d0a079d" xlink:to="loc_us-gaap_UnbilledRevenuesMember_019ff0f8-776b-7c5d-a2b1-3de5a72dfa36" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_019ff0f8-776b-756c-a716-2d87176ff4b9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019ff0f8-776b-7dcc-b63d-55b34af95b0f" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_019ff0f8-776b-756c-a716-2d87176ff4b9" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019ff0f8-776b-7dc0-8a61-a0a7578580ff" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019ff0f8-776b-70bc-90cd-f96a9eb4632b" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019ff0f8-776b-7dc0-8a61-a0a7578580ff" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1_019ff0f8-776b-7915-81a4-81ef683ea61e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConcentrationRiskPercentage1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019ff0f8-776b-70bc-90cd-f96a9eb4632b" xlink:to="loc_us-gaap_ConcentrationRiskPercentage1_019ff0f8-776b-7915-81a4-81ef683ea61e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityRevenueRecognized_019ff0f8-776b-7f38-acd2-eb78a74a5ae0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContractWithCustomerLiabilityRevenueRecognized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019ff0f8-776b-70bc-90cd-f96a9eb4632b" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityRevenueRecognized_019ff0f8-776b-7f38-acd2-eb78a74a5ae0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligation_019ff0f8-776b-7fa0-afbf-d567d91f09a1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueRemainingPerformanceObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019ff0f8-776b-70bc-90cd-f96a9eb4632b" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligation_019ff0f8-776b-7fa0-afbf-d567d91f09a1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_019ff0f8-776b-73ed-b0b9-f088c3974bb4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueRemainingPerformanceObligationPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019ff0f8-776b-70bc-90cd-f96a9eb4632b" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_019ff0f8-776b-73ed-b0b9-f088c3974bb4" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_019ff0f8-776b-728b-9783-76697d513f4c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019ff0f8-776b-70bc-90cd-f96a9eb4632b" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_019ff0f8-776b-728b-9783-76697d513f4c" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerAssetNet_019ff0f8-776b-7cbb-8138-f3759899fa38" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContractWithCustomerAssetNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019ff0f8-776b-70bc-90cd-f96a9eb4632b" xlink:to="loc_us-gaap_ContractWithCustomerAssetNet_019ff0f8-776b-7cbb-8138-f3759899fa38" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.dynatrace.com/role/RevenueRecognitionNarrativeDetails_1" xlink:type="simple" xlink:href="dt-20260930.xsd#RevenueRecognitionNarrativeDetails_1"/>
  <link:definitionLink xlink:role="http://www.dynatrace.com/role/RevenueRecognitionNarrativeDetails_1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_019ff0f8-776b-70bc-90cd-f96a9eb4632b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisaggregationOfRevenueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_019ff0f8-776b-7dcc-b63d-55b34af95b0f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisaggregationOfRevenueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019ff0f8-776b-70bc-90cd-f96a9eb4632b" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_019ff0f8-776b-7dcc-b63d-55b34af95b0f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019ff0f8-776b-7060-bfda-2a1062031ed6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019ff0f8-776b-7dcc-b63d-55b34af95b0f" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019ff0f8-776b-7060-bfda-2a1062031ed6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019ff0f8-776b-7060-bfda-2a1062031ed6_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019ff0f8-776b-7060-bfda-2a1062031ed6" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019ff0f8-776b-7060-bfda-2a1062031ed6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019ff0f8-776b-7699-a5a7-a20dd311b9af" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019ff0f8-776b-7060-bfda-2a1062031ed6" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019ff0f8-776b-7699-a5a7-a20dd311b9af" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerMember_019ff0f8-776b-7623-9c06-3590819c782c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueFromContractWithCustomerMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019ff0f8-776b-7699-a5a7-a20dd311b9af" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerMember_019ff0f8-776b-7623-9c06-3590819c782c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_019ff0f8-776b-7bfa-8c24-119afdafb639" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConcentrationRiskByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019ff0f8-776b-7dcc-b63d-55b34af95b0f" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_019ff0f8-776b-7bfa-8c24-119afdafb639" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_019ff0f8-776b-7bfa-8c24-119afdafb639_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_019ff0f8-776b-7bfa-8c24-119afdafb639" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_019ff0f8-776b-7bfa-8c24-119afdafb639_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_019ff0f8-776b-75e3-ba6f-f42babf956ad" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_019ff0f8-776b-7bfa-8c24-119afdafb639" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_019ff0f8-776b-75e3-ba6f-f42babf956ad" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeographicConcentrationRiskMember_019ff0f8-776b-7bfc-a700-7e0239562cf3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GeographicConcentrationRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_019ff0f8-776b-75e3-ba6f-f42babf956ad" xlink:to="loc_us-gaap_GeographicConcentrationRiskMember_019ff0f8-776b-7bfc-a700-7e0239562cf3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_019ff0f8-776b-701d-be1c-cfcade455e20" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019ff0f8-776b-7dcc-b63d-55b34af95b0f" xlink:to="loc_srt_StatementGeographicalAxis_019ff0f8-776b-701d-be1c-cfcade455e20" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_019ff0f8-776b-701d-be1c-cfcade455e20_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_019ff0f8-776b-701d-be1c-cfcade455e20" xlink:to="loc_srt_SegmentGeographicalDomain_019ff0f8-776b-701d-be1c-cfcade455e20_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_019ff0f8-776b-7835-a960-ab7a3e133dee" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_019ff0f8-776b-701d-be1c-cfcade455e20" xlink:to="loc_srt_SegmentGeographicalDomain_019ff0f8-776b-7835-a960-ab7a3e133dee" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_019ff0f8-776b-7fd4-a8e4-a9031899bb17" xlink:href="https://xbrl.sec.gov/country/2026/country-2026.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019ff0f8-776b-7835-a960-ab7a3e133dee" xlink:to="loc_country_US_019ff0f8-776b-7fd4-a8e4-a9031899bb17" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsNotesLoansAndFinancingReceivablesByBillingStatusTypeAxis_019ff0f8-776b-7ac8-b616-5a7208d7f7d3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsNotesLoansAndFinancingReceivablesByBillingStatusTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019ff0f8-776b-7dcc-b63d-55b34af95b0f" xlink:to="loc_us-gaap_AccountsNotesLoansAndFinancingReceivablesByBillingStatusTypeAxis_019ff0f8-776b-7ac8-b616-5a7208d7f7d3" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReceivablesBillingStatusDomain_019ff0f8-776b-7ac8-b616-5a7208d7f7d3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReceivablesBillingStatusDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AccountsNotesLoansAndFinancingReceivablesByBillingStatusTypeAxis_019ff0f8-776b-7ac8-b616-5a7208d7f7d3" xlink:to="loc_us-gaap_ReceivablesBillingStatusDomain_019ff0f8-776b-7ac8-b616-5a7208d7f7d3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReceivablesBillingStatusDomain_019ff0f8-776b-7d7d-9517-aa618d0a079d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReceivablesBillingStatusDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AccountsNotesLoansAndFinancingReceivablesByBillingStatusTypeAxis_019ff0f8-776b-7ac8-b616-5a7208d7f7d3" xlink:to="loc_us-gaap_ReceivablesBillingStatusDomain_019ff0f8-776b-7d7d-9517-aa618d0a079d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BilledRevenuesMember_019ff0f8-776b-7b42-9eae-a20178282999" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BilledRevenuesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReceivablesBillingStatusDomain_019ff0f8-776b-7d7d-9517-aa618d0a079d" xlink:to="loc_us-gaap_BilledRevenuesMember_019ff0f8-776b-7b42-9eae-a20178282999" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnbilledRevenuesMember_019ff0f8-776b-7c5d-a2b1-3de5a72dfa36" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_UnbilledRevenuesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReceivablesBillingStatusDomain_019ff0f8-776b-7d7d-9517-aa618d0a079d" xlink:to="loc_us-gaap_UnbilledRevenuesMember_019ff0f8-776b-7c5d-a2b1-3de5a72dfa36" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019ff0f8-776b-7dc0-8a61-a0a7578580ff" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019ff0f8-776b-70bc-90cd-f96a9eb4632b" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019ff0f8-776b-7dc0-8a61-a0a7578580ff" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1_019ff0f8-776b-7915-81a4-81ef683ea61e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConcentrationRiskPercentage1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019ff0f8-776b-70bc-90cd-f96a9eb4632b" xlink:to="loc_us-gaap_ConcentrationRiskPercentage1_019ff0f8-776b-7915-81a4-81ef683ea61e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityRevenueRecognized_019ff0f8-776b-7f38-acd2-eb78a74a5ae0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContractWithCustomerLiabilityRevenueRecognized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019ff0f8-776b-70bc-90cd-f96a9eb4632b" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityRevenueRecognized_019ff0f8-776b-7f38-acd2-eb78a74a5ae0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligation_019ff0f8-776b-7fa0-afbf-d567d91f09a1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueRemainingPerformanceObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019ff0f8-776b-70bc-90cd-f96a9eb4632b" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligation_019ff0f8-776b-7fa0-afbf-d567d91f09a1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_019ff0f8-776b-73ed-b0b9-f088c3974bb4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueRemainingPerformanceObligationPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019ff0f8-776b-70bc-90cd-f96a9eb4632b" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_019ff0f8-776b-73ed-b0b9-f088c3974bb4" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_019ff0f8-776b-728b-9783-76697d513f4c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019ff0f8-776b-70bc-90cd-f96a9eb4632b" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_019ff0f8-776b-728b-9783-76697d513f4c" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerAssetNet_019ff0f8-776b-7cbb-8138-f3759899fa38" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContractWithCustomerAssetNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019ff0f8-776b-70bc-90cd-f96a9eb4632b" xlink:to="loc_us-gaap_ContractWithCustomerAssetNet_019ff0f8-776b-7cbb-8138-f3759899fa38" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.dynatrace.com/role/BusinessCombinationsNarrativeDetails" xlink:type="simple" xlink:href="dt-20260930.xsd#BusinessCombinationsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.dynatrace.com/role/BusinessCombinationsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_019ff0f8-776b-78a6-9c95-3e0a841482d0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019ff0f8-776b-7b0f-bb34-1aaad487818c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019ff0f8-776b-78a6-9c95-3e0a841482d0" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019ff0f8-776b-7b0f-bb34-1aaad487818c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_019ff0f8-776b-7d89-900d-a8ad30127527" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019ff0f8-776b-7b0f-bb34-1aaad487818c" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_019ff0f8-776b-7d89-900d-a8ad30127527" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ff0f8-776b-7d89-900d-a8ad30127527_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019ff0f8-776b-7d89-900d-a8ad30127527" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ff0f8-776b-7d89-900d-a8ad30127527_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ff0f8-776b-7aae-8434-12d4c5b15e1c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019ff0f8-776b-7d89-900d-a8ad30127527" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ff0f8-776b-7aae-8434-12d4c5b15e1c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_BindplaneMember_019ff0f8-776b-7b8c-a494-4e398ca80408" xlink:href="dt-20260930.xsd#dt_BindplaneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ff0f8-776b-7aae-8434-12d4c5b15e1c" xlink:to="loc_dt_BindplaneMember_019ff0f8-776b-7b8c-a494-4e398ca80408" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019ff0f8-776b-7744-94fc-2784889d1ab0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019ff0f8-776b-7b0f-bb34-1aaad487818c" xlink:to="loc_us-gaap_AwardTypeAxis_019ff0f8-776b-7744-94fc-2784889d1ab0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ff0f8-776b-7744-94fc-2784889d1ab0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_019ff0f8-776b-7744-94fc-2784889d1ab0" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ff0f8-776b-7744-94fc-2784889d1ab0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ff0f8-776b-7228-9c65-c6e431535d85" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_019ff0f8-776b-7744-94fc-2784889d1ab0" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ff0f8-776b-7228-9c65-c6e431535d85" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_019ff0f8-776b-750a-a63b-83b1248778ef" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ff0f8-776b-7228-9c65-c6e431535d85" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_019ff0f8-776b-750a-a63b-83b1248778ef" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferred1_019ff0f8-776b-7a43-9ce0-71f87a37e495" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationConsiderationTransferred1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019ff0f8-776b-78a6-9c95-3e0a841482d0" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferred1_019ff0f8-776b-7a43-9ce0-71f87a37e495" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesGross_019ff0f8-776b-7bfb-b8d2-7bd2a97dcfbe" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsToAcquireBusinessesGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019ff0f8-776b-78a6-9c95-3e0a841482d0" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesGross_019ff0f8-776b-7bfb-b8d2-7bd2a97dcfbe" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_BusinessCombinationReceivableForPurchasePriceAdjustments_019ff0f8-776b-7c5a-9f2f-a9205bbd4058" xlink:href="dt-20260930.xsd#dt_BusinessCombinationReceivableForPurchasePriceAdjustments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019ff0f8-776b-78a6-9c95-3e0a841482d0" xlink:to="loc_dt_BusinessCombinationReceivableForPurchasePriceAdjustments_019ff0f8-776b-7c5a-9f2f-a9205bbd4058" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuable_019ff0f8-776b-75c0-acfb-58086ebebce6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019ff0f8-776b-78a6-9c95-3e0a841482d0" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuable_019ff0f8-776b-75c0-acfb-58086ebebce6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_019ff0f8-776b-77e2-b2e2-ce47ce8640ed" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019ff0f8-776b-78a6-9c95-3e0a841482d0" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_019ff0f8-776b-77e2-b2e2-ce47ce8640ed" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfReportingUnits_019ff0f8-776b-7b69-a280-ce5a777a20ae" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NumberOfReportingUnits"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019ff0f8-776b-78a6-9c95-3e0a841482d0" xlink:to="loc_us-gaap_NumberOfReportingUnits_019ff0f8-776b-7b69-a280-ce5a777a20ae" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.dynatrace.com/role/AcquisitionsScheduleofRecognizedIdentifiedAssetsAcquiredandLiabilitiesAssumedDetails" xlink:type="simple" xlink:href="dt-20260930.xsd#AcquisitionsScheduleofRecognizedIdentifiedAssetsAcquiredandLiabilitiesAssumedDetails"/>
  <link:definitionLink xlink:role="http://www.dynatrace.com/role/AcquisitionsScheduleofRecognizedIdentifiedAssetsAcquiredandLiabilitiesAssumedDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_019ff0f8-776b-75fb-afa1-be61d4384359" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019ff0f8-776b-76f7-b832-c45f2007eaa2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019ff0f8-776b-75fb-afa1-be61d4384359" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019ff0f8-776b-76f7-b832-c45f2007eaa2" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_019ff0f8-776b-7786-8a1a-96448b8a93e6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019ff0f8-776b-76f7-b832-c45f2007eaa2" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_019ff0f8-776b-7786-8a1a-96448b8a93e6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ff0f8-776b-7786-8a1a-96448b8a93e6_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019ff0f8-776b-7786-8a1a-96448b8a93e6" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ff0f8-776b-7786-8a1a-96448b8a93e6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ff0f8-776b-7598-ae7a-3994dacf93bd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019ff0f8-776b-7786-8a1a-96448b8a93e6" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ff0f8-776b-7598-ae7a-3994dacf93bd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_BindplaneMember_019ff0f8-776b-716d-b11a-a89139d6cc8b" xlink:href="dt-20260930.xsd#dt_BindplaneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ff0f8-776b-7598-ae7a-3994dacf93bd" xlink:to="loc_dt_BindplaneMember_019ff0f8-776b-716d-b11a-a89139d6cc8b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_019ff0f8-776b-7425-9428-01a9995abef4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019ff0f8-776b-75fb-afa1-be61d4384359" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_019ff0f8-776b-7425-9428-01a9995abef4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents_019ff0f8-776b-7fc7-9d23-44058e5e9ed8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_019ff0f8-776b-7425-9428-01a9995abef4" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents_019ff0f8-776b-7fc7-9d23-44058e5e9ed8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_019ff0f8-776b-76dd-8edf-1675a88d2121" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_019ff0f8-776b-7425-9428-01a9995abef4" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_019ff0f8-776b-76dd-8edf-1675a88d2121" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets_019ff0f8-776b-7f89-a42a-1fde535a8cbe" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_019ff0f8-776b-7425-9428-01a9995abef4" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets_019ff0f8-776b-7f89-a42a-1fde535a8cbe" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_019ff0f8-776b-701c-98f9-42d27e83a2be" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_019ff0f8-776b-7425-9428-01a9995abef4" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_019ff0f8-776b-701c-98f9-42d27e83a2be" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_019ff0f8-776b-7db3-b971-5b806cbdaa8a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_019ff0f8-776b-7425-9428-01a9995abef4" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_019ff0f8-776b-7db3-b971-5b806cbdaa8a" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets_019ff0f8-776b-745c-a664-a4ca24c653e4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_019ff0f8-776b-7425-9428-01a9995abef4" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets_019ff0f8-776b-745c-a664-a4ca24c653e4" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract_019ff0f8-776b-70fe-9f3e-6e3e1a687381" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019ff0f8-776b-75fb-afa1-be61d4384359" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract_019ff0f8-776b-70fe-9f3e-6e3e1a687381" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_BusinessCombinationRecognizedLiabilityAssumedAccountsPayableAccruedExpensesAndOtherLiabilities_019ff0f8-776b-78ca-bfd8-37314eac86a5" xlink:href="dt-20260930.xsd#dt_BusinessCombinationRecognizedLiabilityAssumedAccountsPayableAccruedExpensesAndOtherLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract_019ff0f8-776b-70fe-9f3e-6e3e1a687381" xlink:to="loc_dt_BusinessCombinationRecognizedLiabilityAssumedAccountsPayableAccruedExpensesAndOtherLiabilities_019ff0f8-776b-78ca-bfd8-37314eac86a5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue_019ff0f8-776b-727a-b139-793f49be62e1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract_019ff0f8-776b-70fe-9f3e-6e3e1a687381" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue_019ff0f8-776b-727a-b139-793f49be62e1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilities_019ff0f8-776b-7c73-974b-9be2031b89f8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract_019ff0f8-776b-70fe-9f3e-6e3e1a687381" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilities_019ff0f8-776b-7c73-974b-9be2031b89f8" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_019ff0f8-776b-7177-b419-fc7e4635a288" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract_019ff0f8-776b-70fe-9f3e-6e3e1a687381" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_019ff0f8-776b-7177-b419-fc7e4635a288" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet_019ff0f8-776b-74a8-8b1e-9f9f40cb199e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019ff0f8-776b-75fb-afa1-be61d4384359" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet_019ff0f8-776b-74a8-8b1e-9f9f40cb199e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferred1_019ff0f8-776b-7473-a5d1-a250000a0407" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationConsiderationTransferred1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019ff0f8-776b-75fb-afa1-be61d4384359" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferred1_019ff0f8-776b-7473-a5d1-a250000a0407" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_019ff0f8-776b-7191-ab64-067d74f12bc1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019ff0f8-776b-75fb-afa1-be61d4384359" xlink:to="loc_us-gaap_Goodwill_019ff0f8-776b-7191-ab64-067d74f12bc1" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.dynatrace.com/role/BusinessCombinationsBusinessCombinationIntangibleAssetAcquiredFiniteLivedDetails" xlink:type="simple" xlink:href="dt-20260930.xsd#BusinessCombinationsBusinessCombinationIntangibleAssetAcquiredFiniteLivedDetails"/>
  <link:definitionLink xlink:role="http://www.dynatrace.com/role/BusinessCombinationsBusinessCombinationIntangibleAssetAcquiredFiniteLivedDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems_019ff0f8-776b-7597-b2b8-43361e4d3d7f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAcquiredAsPartOfBusinessCombinationTable_019ff0f8-776b-7c08-bfc2-bb5e6788adff" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsAcquiredAsPartOfBusinessCombinationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems_019ff0f8-776b-7597-b2b8-43361e4d3d7f" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAcquiredAsPartOfBusinessCombinationTable_019ff0f8-776b-7c08-bfc2-bb5e6788adff" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_019ff0f8-776b-79e3-bb78-330cf4aa230f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsAcquiredAsPartOfBusinessCombinationTable_019ff0f8-776b-7c08-bfc2-bb5e6788adff" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_019ff0f8-776b-79e3-bb78-330cf4aa230f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ff0f8-776b-79e3-bb78-330cf4aa230f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019ff0f8-776b-79e3-bb78-330cf4aa230f" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ff0f8-776b-79e3-bb78-330cf4aa230f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ff0f8-776b-7eb9-bdc3-bb69043c8f4a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019ff0f8-776b-79e3-bb78-330cf4aa230f" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ff0f8-776b-7eb9-bdc3-bb69043c8f4a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_BindplaneMember_019ff0f8-776b-7d7d-b540-2e92880242d6" xlink:href="dt-20260930.xsd#dt_BindplaneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ff0f8-776b-7eb9-bdc3-bb69043c8f4a" xlink:to="loc_dt_BindplaneMember_019ff0f8-776b-7d7d-b540-2e92880242d6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019ff0f8-776b-79a9-af1e-ee9387089491" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsAcquiredAsPartOfBusinessCombinationTable_019ff0f8-776b-7c08-bfc2-bb5e6788adff" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019ff0f8-776b-79a9-af1e-ee9387089491" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019ff0f8-776b-79a9-af1e-ee9387089491_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019ff0f8-776b-79a9-af1e-ee9387089491" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019ff0f8-776b-79a9-af1e-ee9387089491_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019ff0f8-776b-707b-8b7f-1249b59168fd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019ff0f8-776b-79a9-af1e-ee9387089491" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019ff0f8-776b-707b-8b7f-1249b59168fd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DevelopedTechnologyRightsMember_019ff0f8-776b-7d2f-b9de-0c1dde14a789" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DevelopedTechnologyRightsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019ff0f8-776b-707b-8b7f-1249b59168fd" xlink:to="loc_us-gaap_DevelopedTechnologyRightsMember_019ff0f8-776b-7d2f-b9de-0c1dde14a789" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelationshipsMember_019ff0f8-776b-7ca6-ba61-f791c45d5e95" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CustomerRelationshipsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019ff0f8-776b-707b-8b7f-1249b59168fd" xlink:to="loc_us-gaap_CustomerRelationshipsMember_019ff0f8-776b-7ca6-ba61-f791c45d5e95" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TrademarksAndTradeNamesMember_019ff0f8-776b-7633-9362-c657546b5174" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TrademarksAndTradeNamesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019ff0f8-776b-707b-8b7f-1249b59168fd" xlink:to="loc_us-gaap_TrademarksAndTradeNamesMember_019ff0f8-776b-7633-9362-c657546b5174" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinitelivedIntangibleAssetsAcquired1_019ff0f8-776b-7c29-ae57-0424e0891bef" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinitelivedIntangibleAssetsAcquired1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems_019ff0f8-776b-7597-b2b8-43361e4d3d7f" xlink:to="loc_us-gaap_FinitelivedIntangibleAssetsAcquired1_019ff0f8-776b-7c29-ae57-0424e0891bef" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_019ff0f8-776b-7758-b088-f4088a25fde9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems_019ff0f8-776b-7597-b2b8-43361e4d3d7f" xlink:to="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_019ff0f8-776b-7758-b088-f4088a25fde9" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.dynatrace.com/role/InvestmentsandFairValueMeasurementsScheduleofUnrealizedGainLossonInvestmentsDetails" xlink:type="simple" xlink:href="dt-20260930.xsd#InvestmentsandFairValueMeasurementsScheduleofUnrealizedGainLossonInvestmentsDetails"/>
  <link:definitionLink xlink:role="http://www.dynatrace.com/role/InvestmentsandFairValueMeasurementsScheduleofUnrealizedGainLossonInvestmentsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_019ff0f8-776b-7786-a30c-8b63c066adff" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_019ff0f8-776b-7efb-a69a-1f0725a13723" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_019ff0f8-776b-7786-a30c-8b63c066adff" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_019ff0f8-776b-7efb-a69a-1f0725a13723" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_019ff0f8-776b-7ee8-ab39-ec330a22d00b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_019ff0f8-776b-7efb-a69a-1f0725a13723" xlink:to="loc_us-gaap_FinancialInstrumentAxis_019ff0f8-776b-7ee8-ab39-ec330a22d00b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019ff0f8-776b-7ee8-ab39-ec330a22d00b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_019ff0f8-776b-7ee8-ab39-ec330a22d00b" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019ff0f8-776b-7ee8-ab39-ec330a22d00b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019ff0f8-776b-754a-87f8-148e103fa0dc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_019ff0f8-776b-7ee8-ab39-ec330a22d00b" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019ff0f8-776b-754a-87f8-148e103fa0dc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USTreasurySecuritiesMember_019ff0f8-776b-7918-8ba1-13b652b41597" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_USTreasurySecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019ff0f8-776b-754a-87f8-148e103fa0dc" xlink:to="loc_us-gaap_USTreasurySecuritiesMember_019ff0f8-776b-7918-8ba1-13b652b41597" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateDebtSecuritiesMember_019ff0f8-776b-7456-bf5e-4614421c2c21" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CorporateDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019ff0f8-776b-754a-87f8-148e103fa0dc" xlink:to="loc_us-gaap_CorporateDebtSecuritiesMember_019ff0f8-776b-7456-bf5e-4614421c2c21" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialPaperMember_019ff0f8-776b-7276-b94f-a1f7ab27b0ca" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommercialPaperMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019ff0f8-776b-754a-87f8-148e103fa0dc" xlink:to="loc_us-gaap_CommercialPaperMember_019ff0f8-776b-7276-b94f-a1f7ab27b0ca" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USGovernmentAgenciesDebtSecuritiesMember_019ff0f8-776b-7a23-a9c1-38e455dac7ea" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_USGovernmentAgenciesDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019ff0f8-776b-754a-87f8-148e103fa0dc" xlink:to="loc_us-gaap_USGovernmentAgenciesDebtSecuritiesMember_019ff0f8-776b-7a23-a9c1-38e455dac7ea" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_DebtSecuritiesAvailableForSaleIncludingCashAndCashEquivalentsAmortizedCost_019ff0f8-776b-73c6-acda-0035b40e55bf" xlink:href="dt-20260930.xsd#dt_DebtSecuritiesAvailableForSaleIncludingCashAndCashEquivalentsAmortizedCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_019ff0f8-776b-7786-a30c-8b63c066adff" xlink:to="loc_dt_DebtSecuritiesAvailableForSaleIncludingCashAndCashEquivalentsAmortizedCost_019ff0f8-776b-73c6-acda-0035b40e55bf" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_DebtSecuritiesAvailableForSaleIncludingCashAndCashEquivalentsAccumulatedGrossUnrealizedGainBeforeTax_019ff0f8-776b-744c-ad1c-0657aea495c1" xlink:href="dt-20260930.xsd#dt_DebtSecuritiesAvailableForSaleIncludingCashAndCashEquivalentsAccumulatedGrossUnrealizedGainBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_019ff0f8-776b-7786-a30c-8b63c066adff" xlink:to="loc_dt_DebtSecuritiesAvailableForSaleIncludingCashAndCashEquivalentsAccumulatedGrossUnrealizedGainBeforeTax_019ff0f8-776b-744c-ad1c-0657aea495c1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_DebtSecuritiesAvailableForSaleIncludingCashAndCashEquivalentsAccumulatedGrossUnrealizedLossBeforeTax_019ff0f8-776b-75c6-a908-50a4ebad18d7" xlink:href="dt-20260930.xsd#dt_DebtSecuritiesAvailableForSaleIncludingCashAndCashEquivalentsAccumulatedGrossUnrealizedLossBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_019ff0f8-776b-7786-a30c-8b63c066adff" xlink:to="loc_dt_DebtSecuritiesAvailableForSaleIncludingCashAndCashEquivalentsAccumulatedGrossUnrealizedLossBeforeTax_019ff0f8-776b-75c6-a908-50a4ebad18d7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_DebtSecuritiesAvailableForSaleIncludingCashAndCashEquivalents_019ff0f8-776b-7793-a546-7950f3ee49e0" xlink:href="dt-20260930.xsd#dt_DebtSecuritiesAvailableForSaleIncludingCashAndCashEquivalents"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_019ff0f8-776b-7786-a30c-8b63c066adff" xlink:to="loc_dt_DebtSecuritiesAvailableForSaleIncludingCashAndCashEquivalents_019ff0f8-776b-7793-a546-7950f3ee49e0" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.dynatrace.com/role/InvestmentsandFairValueMeasurementsNarrativeDetails" xlink:type="simple" xlink:href="dt-20260930.xsd#InvestmentsandFairValueMeasurementsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.dynatrace.com/role/InvestmentsandFairValueMeasurementsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_019ff0f8-776b-7d52-8923-1bb043ebae4d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_019ff0f8-776b-71d9-a782-fc919bdd83c8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_019ff0f8-776b-7d52-8923-1bb043ebae4d" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_019ff0f8-776b-71d9-a782-fc919bdd83c8" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_019ff0f8-776b-720a-86d0-3dc4ad7901d0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_019ff0f8-776b-71d9-a782-fc919bdd83c8" xlink:to="loc_us-gaap_FinancialInstrumentAxis_019ff0f8-776b-720a-86d0-3dc4ad7901d0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019ff0f8-776b-720a-86d0-3dc4ad7901d0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_019ff0f8-776b-720a-86d0-3dc4ad7901d0" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019ff0f8-776b-720a-86d0-3dc4ad7901d0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019ff0f8-776b-7995-af36-22fbbb473a4e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_019ff0f8-776b-720a-86d0-3dc4ad7901d0" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019ff0f8-776b-7995-af36-22fbbb473a4e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MutualFundMember_019ff0f8-776b-7e74-bfce-89574660465f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MutualFundMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019ff0f8-776b-7995-af36-22fbbb473a4e" xlink:to="loc_us-gaap_MutualFundMember_019ff0f8-776b-7e74-bfce-89574660465f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_019ff0f8-776b-71e7-a178-379731828896" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_019ff0f8-776b-7d52-8923-1bb043ebae4d" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_019ff0f8-776b-71e7-a178-379731828896" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeDebtSecuritiesAvailableForSaleOperating_019ff0f8-776b-75be-a2dc-d6d503dbb26e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestIncomeDebtSecuritiesAvailableForSaleOperating"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_019ff0f8-776b-7d52-8923-1bb043ebae4d" xlink:to="loc_us-gaap_InterestIncomeDebtSecuritiesAvailableForSaleOperating_019ff0f8-776b-75be-a2dc-d6d503dbb26e" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.dynatrace.com/role/InvestmentsandFairValueMeasurementsScheduleofFairValueAssetsandLiabilitiesMeasuredonRecurringBasisDetails" xlink:type="simple" xlink:href="dt-20260930.xsd#InvestmentsandFairValueMeasurementsScheduleofFairValueAssetsandLiabilitiesMeasuredonRecurringBasisDetails"/>
  <link:definitionLink xlink:role="http://www.dynatrace.com/role/InvestmentsandFairValueMeasurementsScheduleofFairValueAssetsandLiabilitiesMeasuredonRecurringBasisDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019ff0f8-776b-71c4-aa9a-369cfd70a268" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019ff0f8-776b-7d45-aadd-29d8d5e06014" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019ff0f8-776b-71c4-aa9a-369cfd70a268" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019ff0f8-776b-7d45-aadd-29d8d5e06014" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019ff0f8-776b-7a17-91dd-4ed73b1add66" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019ff0f8-776b-7d45-aadd-29d8d5e06014" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019ff0f8-776b-7a17-91dd-4ed73b1add66" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019ff0f8-776b-7a17-91dd-4ed73b1add66_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019ff0f8-776b-7a17-91dd-4ed73b1add66" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019ff0f8-776b-7a17-91dd-4ed73b1add66_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019ff0f8-776b-73f7-8938-0d43c3ea67e9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019ff0f8-776b-7a17-91dd-4ed73b1add66" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019ff0f8-776b-73f7-8938-0d43c3ea67e9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_019ff0f8-776b-7a9b-b9e7-3df75a25b95d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019ff0f8-776b-73f7-8938-0d43c3ea67e9" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_019ff0f8-776b-7a9b-b9e7-3df75a25b95d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_019ff0f8-776b-7499-bd5d-0b3762bd3baf" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019ff0f8-776b-73f7-8938-0d43c3ea67e9" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_019ff0f8-776b-7499-bd5d-0b3762bd3baf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_019ff0f8-776b-7c52-b1dc-af26dc88b9c5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019ff0f8-776b-73f7-8938-0d43c3ea67e9" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_019ff0f8-776b-7c52-b1dc-af26dc88b9c5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAxis_019ff0f8-776b-7096-8b45-46b712154701" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashAndCashEquivalentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019ff0f8-776b-7d45-aadd-29d8d5e06014" xlink:to="loc_us-gaap_CashAndCashEquivalentsAxis_019ff0f8-776b-7096-8b45-46b712154701" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_019ff0f8-776b-7096-8b45-46b712154701_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CashAndCashEquivalentsAxis_019ff0f8-776b-7096-8b45-46b712154701" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_019ff0f8-776b-7096-8b45-46b712154701_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_019ff0f8-776b-71b9-81c9-32277bad748c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CashAndCashEquivalentsAxis_019ff0f8-776b-7096-8b45-46b712154701" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_019ff0f8-776b-71b9-81c9-32277bad748c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MoneyMarketFundsMember_019ff0f8-776b-753f-9a18-9a8f11b28763" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MoneyMarketFundsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_019ff0f8-776b-71b9-81c9-32277bad748c" xlink:to="loc_us-gaap_MoneyMarketFundsMember_019ff0f8-776b-753f-9a18-9a8f11b28763" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USTreasurySecuritiesMember_019ff0f8-776b-70a2-b5df-81000bd32a4e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_USTreasurySecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_019ff0f8-776b-71b9-81c9-32277bad748c" xlink:to="loc_us-gaap_USTreasurySecuritiesMember_019ff0f8-776b-70a2-b5df-81000bd32a4e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialPaperMember_01a11f3a-cf02-717b-b6c0-d8e3b563b6a4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommercialPaperMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_019ff0f8-776b-71b9-81c9-32277bad748c" xlink:to="loc_us-gaap_CommercialPaperMember_01a11f3a-cf02-717b-b6c0-d8e3b563b6a4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_019ff0f8-776b-7264-a14c-9776ed89e228" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019ff0f8-776b-7d45-aadd-29d8d5e06014" xlink:to="loc_us-gaap_FinancialInstrumentAxis_019ff0f8-776b-7264-a14c-9776ed89e228" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019ff0f8-776b-7264-a14c-9776ed89e228_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_019ff0f8-776b-7264-a14c-9776ed89e228" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019ff0f8-776b-7264-a14c-9776ed89e228_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019ff0f8-776b-7ff9-abbe-63b1ec002b3e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_019ff0f8-776b-7264-a14c-9776ed89e228" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019ff0f8-776b-7ff9-abbe-63b1ec002b3e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MutualFundMember_019ff0f8-776b-7c35-b0ed-75eb41eca91f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MutualFundMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019ff0f8-776b-7ff9-abbe-63b1ec002b3e" xlink:to="loc_us-gaap_MutualFundMember_019ff0f8-776b-7c35-b0ed-75eb41eca91f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USTreasurySecuritiesMember_019ff0f8-776b-7706-b651-8fc80a489c57" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_USTreasurySecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019ff0f8-776b-7ff9-abbe-63b1ec002b3e" xlink:to="loc_us-gaap_USTreasurySecuritiesMember_019ff0f8-776b-7706-b651-8fc80a489c57" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateDebtSecuritiesMember_019ff0f8-776b-72e4-acae-9b2230f869f7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CorporateDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019ff0f8-776b-7ff9-abbe-63b1ec002b3e" xlink:to="loc_us-gaap_CorporateDebtSecuritiesMember_019ff0f8-776b-72e4-acae-9b2230f869f7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialPaperMember_019ff0f8-776b-7b70-8971-09879641d04f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommercialPaperMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019ff0f8-776b-7ff9-abbe-63b1ec002b3e" xlink:to="loc_us-gaap_CommercialPaperMember_019ff0f8-776b-7b70-8971-09879641d04f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USGovernmentAgenciesDebtSecuritiesMember_019ff0f8-776b-76b7-9bef-a4d80118d854" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_USGovernmentAgenciesDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019ff0f8-776b-7ff9-abbe-63b1ec002b3e" xlink:to="loc_us-gaap_USGovernmentAgenciesDebtSecuritiesMember_019ff0f8-776b-76b7-9bef-a4d80118d854" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsFairValueDisclosureAbstract_019ff0f8-776b-7e89-9345-2dc7b572c7e0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsFairValueDisclosureAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019ff0f8-776b-71c4-aa9a-369cfd70a268" xlink:to="loc_us-gaap_AssetsFairValueDisclosureAbstract_019ff0f8-776b-7e89-9345-2dc7b572c7e0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_019ff0f8-776b-7741-8769-9e2346f294c6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashAndCashEquivalentsFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_019ff0f8-776b-7e89-9345-2dc7b572c7e0" xlink:to="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_019ff0f8-776b-7741-8769-9e2346f294c6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_019ff0f8-776b-7102-9a51-ace4b12491c2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_019ff0f8-776b-7e89-9345-2dc7b572c7e0" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_019ff0f8-776b-7102-9a51-ace4b12491c2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsFairValueDisclosure_019ff0f8-776b-749a-a159-5398f387cfae" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_019ff0f8-776b-7e89-9345-2dc7b572c7e0" xlink:to="loc_us-gaap_AssetsFairValueDisclosure_019ff0f8-776b-749a-a159-5398f387cfae" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.dynatrace.com/role/GoodwillandOtherIntangibleAssetsNetScheduleofIntangibleAssetsNetExcludingGoodwillDetails" xlink:type="simple" xlink:href="dt-20260930.xsd#GoodwillandOtherIntangibleAssetsNetScheduleofIntangibleAssetsNetExcludingGoodwillDetails"/>
  <link:definitionLink xlink:role="http://www.dynatrace.com/role/GoodwillandOtherIntangibleAssetsNetScheduleofIntangibleAssetsNetExcludingGoodwillDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019ff0f8-776b-7d5b-8a51-e7bc7b7c9fd2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_019ff0f8-776b-7f36-93c8-26399a29c8e1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019ff0f8-776b-7d5b-8a51-e7bc7b7c9fd2" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_019ff0f8-776b-7f36-93c8-26399a29c8e1" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019ff0f8-776b-771e-958a-25283a103b89" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_019ff0f8-776b-7f36-93c8-26399a29c8e1" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019ff0f8-776b-771e-958a-25283a103b89" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019ff0f8-776b-771e-958a-25283a103b89_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019ff0f8-776b-771e-958a-25283a103b89" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019ff0f8-776b-771e-958a-25283a103b89_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019ff0f8-776b-774a-a534-a0b1bde77cf5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019ff0f8-776b-771e-958a-25283a103b89" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019ff0f8-776b-774a-a534-a0b1bde77cf5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SoftwareAndSoftwareDevelopmentCostsMember_019ff0f8-776b-740d-ad2d-1a53926d02c4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SoftwareAndSoftwareDevelopmentCostsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019ff0f8-776b-774a-a534-a0b1bde77cf5" xlink:to="loc_us-gaap_SoftwareAndSoftwareDevelopmentCostsMember_019ff0f8-776b-740d-ad2d-1a53926d02c4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelationshipsMember_019ff0f8-776b-717a-a58d-85c507f1beaa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CustomerRelationshipsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019ff0f8-776b-774a-a534-a0b1bde77cf5" xlink:to="loc_us-gaap_CustomerRelationshipsMember_019ff0f8-776b-717a-a58d-85c507f1beaa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TrademarksAndTradeNamesMember_019ff0f8-776b-73a1-be97-f3e4be3aee1d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TrademarksAndTradeNamesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019ff0f8-776b-774a-a534-a0b1bde77cf5" xlink:to="loc_us-gaap_TrademarksAndTradeNamesMember_019ff0f8-776b-73a1-be97-f3e4be3aee1d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_019ff0f8-776b-7929-8eff-b9b34b6fcb33" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019ff0f8-776b-7d5b-8a51-e7bc7b7c9fd2" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_019ff0f8-776b-7929-8eff-b9b34b6fcb33" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_019ff0f8-776b-7fbf-8a28-effb397fa1f8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019ff0f8-776b-7d5b-8a51-e7bc7b7c9fd2" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_019ff0f8-776b-7fbf-8a28-effb397fa1f8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_019ff0f8-776b-701a-9531-71016bc6d3eb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019ff0f8-776b-7d5b-8a51-e7bc7b7c9fd2" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_019ff0f8-776b-701a-9531-71016bc6d3eb" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.dynatrace.com/role/LongtermDebtNarrativeDetails" xlink:type="simple" xlink:href="dt-20260930.xsd#LongtermDebtNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.dynatrace.com/role/LongtermDebtNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityLineItems_01a11f2b-c7c7-7829-a769-266e0e31129d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditFacilityLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityTable_01a11f2b-c7c7-7a42-bf7d-1baa56be37de" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditFacilityTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_01a11f2b-c7c7-7829-a769-266e0e31129d" xlink:to="loc_us-gaap_LineOfCreditFacilityTable_01a11f2b-c7c7-7a42-bf7d-1baa56be37de" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_01a11f2b-c7c7-740e-96d0-1e460cebec56" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_01a11f2b-c7c7-7a42-bf7d-1baa56be37de" xlink:to="loc_us-gaap_DebtInstrumentAxis_01a11f2b-c7c7-740e-96d0-1e460cebec56" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_01a11f2b-c7c7-740e-96d0-1e460cebec56_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_01a11f2b-c7c7-740e-96d0-1e460cebec56" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_01a11f2b-c7c7-740e-96d0-1e460cebec56_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_01a11f2b-c7c7-73d0-8d5c-387842ccb05a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_01a11f2b-c7c7-740e-96d0-1e460cebec56" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_01a11f2b-c7c7-73d0-8d5c-387842ccb05a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_A2031NotesMember_01a11f2b-c7c7-74d2-99de-b3956083ac3b" xlink:href="dt-20260930.xsd#dt_A2031NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a11f2b-c7c7-73d0-8d5c-387842ccb05a" xlink:to="loc_dt_A2031NotesMember_01a11f2b-c7c7-74d2-99de-b3956083ac3b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_A2022CreditFacilityMember_01a11f2c-337f-7f07-b643-2629a7e6f117" xlink:href="dt-20260930.xsd#dt_A2022CreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a11f2b-c7c7-73d0-8d5c-387842ccb05a" xlink:to="loc_dt_A2022CreditFacilityMember_01a11f2c-337f-7f07-b643-2629a7e6f117" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_A2026CreditFacilityMember_01a11f2c-337f-7c30-9290-ca9373eda7b4" xlink:href="dt-20260930.xsd#dt_A2026CreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a11f2b-c7c7-73d0-8d5c-387842ccb05a" xlink:to="loc_dt_A2026CreditFacilityMember_01a11f2c-337f-7c30-9290-ca9373eda7b4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_A2026CreditFacilityNonUSDollarDenominatedBorrowingsSublimitMember_01a17a2e-d71a-7d7c-a233-d6c7bea5cb8c" xlink:href="dt-20260930.xsd#dt_A2026CreditFacilityNonUSDollarDenominatedBorrowingsSublimitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dt_A2026CreditFacilityMember_01a11f2c-337f-7c30-9290-ca9373eda7b4" xlink:to="loc_dt_A2026CreditFacilityNonUSDollarDenominatedBorrowingsSublimitMember_01a17a2e-d71a-7d7c-a233-d6c7bea5cb8c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_01a11f2b-c7c7-77b3-a657-30189a36903b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_01a11f2b-c7c7-7a42-bf7d-1baa56be37de" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_01a11f2b-c7c7-77b3-a657-30189a36903b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_01a11f2b-c7c7-77b3-a657-30189a36903b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_01a11f2b-c7c7-77b3-a657-30189a36903b" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_01a11f2b-c7c7-77b3-a657-30189a36903b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_01a11f2b-c7c7-7cf4-b2dd-8f171330bcca" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_01a11f2b-c7c7-77b3-a657-30189a36903b" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_01a11f2b-c7c7-7cf4-b2dd-8f171330bcca" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConvertibleDebtMember_01a11f2b-c7c7-7d6f-85b8-f8bab2e4fcd2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConvertibleDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_01a11f2b-c7c7-7cf4-b2dd-8f171330bcca" xlink:to="loc_us-gaap_ConvertibleDebtMember_01a11f2b-c7c7-7d6f-85b8-f8bab2e4fcd2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_01a11f2b-c7c7-7d54-833e-3cf81ac0b531" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_01a11f2b-c7c7-7cf4-b2dd-8f171330bcca" xlink:to="loc_us-gaap_LineOfCreditMember_01a11f2b-c7c7-7d54-833e-3cf81ac0b531" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_DebtInstrumentConvertibleTermsOfConversionAxis_01a11f2b-c7c7-7bd4-97c8-8d198b3eaa63" xlink:href="dt-20260930.xsd#dt_DebtInstrumentConvertibleTermsOfConversionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_01a11f2b-c7c7-7a42-bf7d-1baa56be37de" xlink:to="loc_dt_DebtInstrumentConvertibleTermsOfConversionAxis_01a11f2b-c7c7-7bd4-97c8-8d198b3eaa63" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_DebtInstrumentConvertibleTermsOfConversionDomain_01a11f2b-c7c7-7bd4-97c8-8d198b3eaa63_default" xlink:href="dt-20260930.xsd#dt_DebtInstrumentConvertibleTermsOfConversionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dt_DebtInstrumentConvertibleTermsOfConversionAxis_01a11f2b-c7c7-7bd4-97c8-8d198b3eaa63" xlink:to="loc_dt_DebtInstrumentConvertibleTermsOfConversionDomain_01a11f2b-c7c7-7bd4-97c8-8d198b3eaa63_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_DebtInstrumentConvertibleTermsOfConversionDomain_01a11f2b-c7c7-7f1c-8b4e-b8dceeab490c" xlink:href="dt-20260930.xsd#dt_DebtInstrumentConvertibleTermsOfConversionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dt_DebtInstrumentConvertibleTermsOfConversionAxis_01a11f2b-c7c7-7bd4-97c8-8d198b3eaa63" xlink:to="loc_dt_DebtInstrumentConvertibleTermsOfConversionDomain_01a11f2b-c7c7-7f1c-8b4e-b8dceeab490c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_DebtExchangeableTermsOneMember_01a11f2b-c7c7-77cc-980d-23c27e7d1551" xlink:href="dt-20260930.xsd#dt_DebtExchangeableTermsOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dt_DebtInstrumentConvertibleTermsOfConversionDomain_01a11f2b-c7c7-7f1c-8b4e-b8dceeab490c" xlink:to="loc_dt_DebtExchangeableTermsOneMember_01a11f2b-c7c7-77cc-980d-23c27e7d1551" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_DebtExchangeableTermsTwoMember_01a11f2b-c7c7-7f9d-96bb-d9817517161e" xlink:href="dt-20260930.xsd#dt_DebtExchangeableTermsTwoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dt_DebtInstrumentConvertibleTermsOfConversionDomain_01a11f2b-c7c7-7f1c-8b4e-b8dceeab490c" xlink:to="loc_dt_DebtExchangeableTermsTwoMember_01a11f2b-c7c7-7f9d-96bb-d9817517161e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_01a11f2b-c7c7-7cec-9a98-6de330293dc4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_01a11f2b-c7c7-7a42-bf7d-1baa56be37de" xlink:to="loc_us-gaap_CreditFacilityAxis_01a11f2b-c7c7-7cec-9a98-6de330293dc4" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_01a11f2b-c7c7-7cec-9a98-6de330293dc4_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_01a11f2b-c7c7-7cec-9a98-6de330293dc4" xlink:to="loc_us-gaap_CreditFacilityDomain_01a11f2b-c7c7-7cec-9a98-6de330293dc4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_01a11f2b-c7c7-7fb8-8d8e-9fd261f3e98f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_01a11f2b-c7c7-7cec-9a98-6de330293dc4" xlink:to="loc_us-gaap_CreditFacilityDomain_01a11f2b-c7c7-7fb8-8d8e-9fd261f3e98f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_01a11f2b-c7c7-7d88-9e2b-c86ca1739cb8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_01a11f2b-c7c7-7fb8-8d8e-9fd261f3e98f" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_01a11f2b-c7c7-7d88-9e2b-c86ca1739cb8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BridgeLoanMember_01a11f2c-337f-71b5-9648-cfcbbdac468f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BridgeLoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_01a11f2b-c7c7-7fb8-8d8e-9fd261f3e98f" xlink:to="loc_us-gaap_BridgeLoanMember_01a11f2c-337f-71b5-9648-cfcbbdac468f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LetterOfCreditMember_01a11f2c-337f-7376-b767-98ca1ce4ff64" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LetterOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_01a11f2b-c7c7-7fb8-8d8e-9fd261f3e98f" xlink:to="loc_us-gaap_LetterOfCreditMember_01a11f2c-337f-7376-b767-98ca1ce4ff64" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OptionIndexedToIssuersEquityTypeAxis_01a11f2c-337f-7cb1-a9a1-5d0fd3b49378" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OptionIndexedToIssuersEquityTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_01a11f2b-c7c7-7a42-bf7d-1baa56be37de" xlink:to="loc_us-gaap_OptionIndexedToIssuersEquityTypeAxis_01a11f2c-337f-7cb1-a9a1-5d0fd3b49378" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OptionIndexedToIssuersEquityTypeDomain_01a11f2c-337f-7cb1-a9a1-5d0fd3b49378_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OptionIndexedToIssuersEquityTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_OptionIndexedToIssuersEquityTypeAxis_01a11f2c-337f-7cb1-a9a1-5d0fd3b49378" xlink:to="loc_us-gaap_OptionIndexedToIssuersEquityTypeDomain_01a11f2c-337f-7cb1-a9a1-5d0fd3b49378_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OptionIndexedToIssuersEquityTypeDomain_01a11f2c-337f-7e4f-bd99-73fe4d39d4e4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OptionIndexedToIssuersEquityTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_OptionIndexedToIssuersEquityTypeAxis_01a11f2c-337f-7cb1-a9a1-5d0fd3b49378" xlink:to="loc_us-gaap_OptionIndexedToIssuersEquityTypeDomain_01a11f2c-337f-7e4f-bd99-73fe4d39d4e4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CallOptionMember_01a11f2c-337f-79ef-9a17-776896254220" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CallOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OptionIndexedToIssuersEquityTypeDomain_01a11f2c-337f-7e4f-bd99-73fe4d39d4e4" xlink:to="loc_us-gaap_CallOptionMember_01a11f2c-337f-79ef-9a17-776896254220" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightAxis_01a11f2c-337f-7dcc-8e89-e62aa684bf91" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfWarrantOrRightAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_01a11f2b-c7c7-7a42-bf7d-1baa56be37de" xlink:to="loc_us-gaap_ClassOfWarrantOrRightAxis_01a11f2c-337f-7dcc-8e89-e62aa684bf91" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightDomain_01a11f2c-337f-7dcc-8e89-e62aa684bf91_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfWarrantOrRightDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ClassOfWarrantOrRightAxis_01a11f2c-337f-7dcc-8e89-e62aa684bf91" xlink:to="loc_us-gaap_ClassOfWarrantOrRightDomain_01a11f2c-337f-7dcc-8e89-e62aa684bf91_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightDomain_01a11f2c-337f-75d3-a9d7-b7e9f13c3a09" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfWarrantOrRightDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ClassOfWarrantOrRightAxis_01a11f2c-337f-7dcc-8e89-e62aa684bf91" xlink:to="loc_us-gaap_ClassOfWarrantOrRightDomain_01a11f2c-337f-75d3-a9d7-b7e9f13c3a09" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_A2031WarrantsMember_01a11f2c-337f-7be4-8c93-5486b38465bc" xlink:href="dt-20260930.xsd#dt_A2031WarrantsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfWarrantOrRightDomain_01a11f2c-337f-75d3-a9d7-b7e9f13c3a09" xlink:to="loc_dt_A2031WarrantsMember_01a11f2c-337f-7be4-8c93-5486b38465bc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_01a11f2b-c7c7-783d-9fe8-5a7ac8da11c5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_01a11f2b-c7c7-7829-a769-266e0e31129d" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_01a11f2b-c7c7-783d-9fe8-5a7ac8da11c5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredFinanceCostsGross_01a11f2c-337f-7afc-8308-55472eac3532" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredFinanceCostsGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_01a11f2b-c7c7-7829-a769-266e0e31129d" xlink:to="loc_us-gaap_DeferredFinanceCostsGross_01a11f2c-337f-7afc-8308-55472eac3532" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentConvertibleConversionRatio1_01a143d7-85de-708d-bcd1-1fe8d050c740" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentConvertibleConversionRatio1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_01a11f2b-c7c7-7829-a769-266e0e31129d" xlink:to="loc_us-gaap_DebtInstrumentConvertibleConversionRatio1_01a143d7-85de-708d-bcd1-1fe8d050c740" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentConvertibleConversionPrice1_01a11f2b-c7c7-7972-a4e1-43e407971a90" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentConvertibleConversionPrice1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_01a11f2b-c7c7-7829-a769-266e0e31129d" xlink:to="loc_us-gaap_DebtInstrumentConvertibleConversionPrice1_01a11f2b-c7c7-7972-a4e1-43e407971a90" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentConvertibleNumberOfEquityInstruments_01a16234-b06e-7fbf-8714-6224bd03facd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentConvertibleNumberOfEquityInstruments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_01a11f2b-c7c7-7829-a769-266e0e31129d" xlink:to="loc_us-gaap_DebtInstrumentConvertibleNumberOfEquityInstruments_01a16234-b06e-7fbf-8714-6224bd03facd" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_DebtInstrumentConvertibleExchangePremiumPercentage_01a11f2b-c7c7-74f1-9448-dbefcffb41ea" xlink:href="dt-20260930.xsd#dt_DebtInstrumentConvertibleExchangePremiumPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_01a11f2b-c7c7-7829-a769-266e0e31129d" xlink:to="loc_dt_DebtInstrumentConvertibleExchangePremiumPercentage_01a11f2b-c7c7-74f1-9448-dbefcffb41ea" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharePrice_01a11f2b-c7c7-7a99-a69b-3d23ff6a82c9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SharePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_01a11f2b-c7c7-7829-a769-266e0e31129d" xlink:to="loc_us-gaap_SharePrice_01a11f2b-c7c7-7a99-a69b-3d23ff6a82c9" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentConvertibleThresholdTradingDays_01a11f2b-c7c7-7dcd-a566-bd8b23ad65b2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentConvertibleThresholdTradingDays"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_01a11f2b-c7c7-7829-a769-266e0e31129d" xlink:to="loc_us-gaap_DebtInstrumentConvertibleThresholdTradingDays_01a11f2b-c7c7-7dcd-a566-bd8b23ad65b2" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentConvertibleThresholdConsecutiveTradingDays1_01a11f2b-c7c7-78be-ab0f-4595b3494dde" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentConvertibleThresholdConsecutiveTradingDays1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_01a11f2b-c7c7-7829-a769-266e0e31129d" xlink:to="loc_us-gaap_DebtInstrumentConvertibleThresholdConsecutiveTradingDays1_01a11f2b-c7c7-78be-ab0f-4595b3494dde" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentConvertibleThresholdPercentageOfStockPriceTrigger_01a11f2b-c7c7-7566-b478-f0e8ca83e9b2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentConvertibleThresholdPercentageOfStockPriceTrigger"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_01a11f2b-c7c7-7829-a769-266e0e31129d" xlink:to="loc_us-gaap_DebtInstrumentConvertibleThresholdPercentageOfStockPriceTrigger_01a11f2b-c7c7-7566-b478-f0e8ca83e9b2" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_DebtInstrumentRedemptionThresholdPercentageOfStockPriceTrigger_01a11f2b-c7c7-77be-95d3-43b64eac5b4e" xlink:href="dt-20260930.xsd#dt_DebtInstrumentRedemptionThresholdPercentageOfStockPriceTrigger"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_01a11f2b-c7c7-7829-a769-266e0e31129d" xlink:to="loc_dt_DebtInstrumentRedemptionThresholdPercentageOfStockPriceTrigger_01a11f2b-c7c7-77be-95d3-43b64eac5b4e" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_DebtInstrumentRedemptionThresholdTradingDays_01a11f2b-c7c7-7c92-b718-b0d667ea109e" xlink:href="dt-20260930.xsd#dt_DebtInstrumentRedemptionThresholdTradingDays"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_01a11f2b-c7c7-7829-a769-266e0e31129d" xlink:to="loc_dt_DebtInstrumentRedemptionThresholdTradingDays_01a11f2b-c7c7-7c92-b718-b0d667ea109e" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_DebtInstrumentRedemptionThresholdConsecutiveTradingDays_01a11f2b-c7c7-79c6-af86-22a1f20aa639" xlink:href="dt-20260930.xsd#dt_DebtInstrumentRedemptionThresholdConsecutiveTradingDays"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_01a11f2b-c7c7-7829-a769-266e0e31129d" xlink:to="loc_dt_DebtInstrumentRedemptionThresholdConsecutiveTradingDays_01a11f2b-c7c7-79c6-af86-22a1f20aa639" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_DebtInstrumentRedemptionThresholdPrincipalAmount_01a11f2b-c7c7-73af-ba20-304b10b44696" xlink:href="dt-20260930.xsd#dt_DebtInstrumentRedemptionThresholdPrincipalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_01a11f2b-c7c7-7829-a769-266e0e31129d" xlink:to="loc_dt_DebtInstrumentRedemptionThresholdPrincipalAmount_01a11f2b-c7c7-73af-ba20-304b10b44696" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPricePercentage_01a11f2b-c7c7-7628-9569-8c06431588ae" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentRedemptionPricePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_01a11f2b-c7c7-7829-a769-266e0e31129d" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPricePercentage_01a11f2b-c7c7-7628-9569-8c06431588ae" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForHedgeFinancingActivities_01a16231-acb4-7e09-bb0e-8df47bd9da6d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsForHedgeFinancingActivities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_01a11f2b-c7c7-7829-a769-266e0e31129d" xlink:to="loc_us-gaap_PaymentsForHedgeFinancingActivities_01a16231-acb4-7e09-bb0e-8df47bd9da6d" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OptionIndexedToIssuersEquityShares_01a11f2c-337f-77b1-86e4-bcdfa5281c35" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OptionIndexedToIssuersEquityShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_01a11f2b-c7c7-7829-a769-266e0e31129d" xlink:to="loc_us-gaap_OptionIndexedToIssuersEquityShares_01a11f2c-337f-77b1-86e4-bcdfa5281c35" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OptionIndexedToIssuersEquityStrikePrice1_01a11f2c-337f-74da-91b2-0be49c298c3f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OptionIndexedToIssuersEquityStrikePrice1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_01a11f2b-c7c7-7829-a769-266e0e31129d" xlink:to="loc_us-gaap_OptionIndexedToIssuersEquityStrikePrice1_01a11f2c-337f-74da-91b2-0be49c298c3f" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights_01a17a11-5ba4-73b8-9ee9-f7d8c5aa2aab" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_01a11f2b-c7c7-7829-a769-266e0e31129d" xlink:to="loc_us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights_01a17a11-5ba4-73b8-9ee9-f7d8c5aa2aab" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_01a17a12-348f-7dca-b38d-d174a2dc6de8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_01a11f2b-c7c7-7829-a769-266e0e31129d" xlink:to="loc_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_01a17a12-348f-7dca-b38d-d174a2dc6de8" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfWarrants_01a143b0-0846-7d16-a174-7e73c624ed89" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromIssuanceOfWarrants"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_01a11f2b-c7c7-7829-a769-266e0e31129d" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfWarrants_01a143b0-0846-7d16-a174-7e73c624ed89" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetsHedgingTransactions_01a16225-9103-7af8-98d0-caded08a7b80" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredTaxAssetsHedgingTransactions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_01a11f2b-c7c7-7829-a769-266e0e31129d" xlink:to="loc_us-gaap_DeferredTaxAssetsHedgingTransactions_01a16225-9103-7af8-98d0-caded08a7b80" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_LineOfCreditFacilityAmountTerminated_01a188c7-e4ea-7e72-8be4-29af69a7214c" xlink:href="dt-20260930.xsd#dt_LineOfCreditFacilityAmountTerminated"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_01a11f2b-c7c7-7829-a769-266e0e31129d" xlink:to="loc_dt_LineOfCreditFacilityAmountTerminated_01a188c7-e4ea-7e72-8be4-29af69a7214c" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfFinancingCosts_01a17a16-6d25-74dc-9b70-556b6567c29d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AmortizationOfFinancingCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_01a11f2b-c7c7-7829-a769-266e0e31129d" xlink:to="loc_us-gaap_AmortizationOfFinancingCosts_01a17a16-6d25-74dc-9b70-556b6567c29d" xlink:type="arc" order="23"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_01a17a14-5ebf-7043-b4b4-df578e43a01e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_01a11f2b-c7c7-7829-a769-266e0e31129d" xlink:to="loc_us-gaap_LongTermDebt_01a17a14-5ebf-7043-b4b4-df578e43a01e" xlink:type="arc" order="24"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_01a11f2c-337f-7dd4-91f0-3d60a141c771" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_01a11f2b-c7c7-7829-a769-266e0e31129d" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_01a11f2c-337f-7dd4-91f0-3d60a141c771" xlink:type="arc" order="25"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_01a143b0-4d75-7e1b-9e4b-58987ffdbca7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_01a11f2b-c7c7-7829-a769-266e0e31129d" xlink:to="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_01a143b0-4d75-7e1b-9e4b-58987ffdbca7" xlink:type="arc" order="26"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LettersOfCreditOutstandingAmount_01a17e15-57d5-7636-829a-f0292f39f2cc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LettersOfCreditOutstandingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_01a11f2b-c7c7-7829-a769-266e0e31129d" xlink:to="loc_us-gaap_LettersOfCreditOutstandingAmount_01a17e15-57d5-7636-829a-f0292f39f2cc" xlink:type="arc" order="27"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_DebtInstrumentNumberOfOptionalExtensions_01a17e13-502a-7c3b-aee9-d01232eb7408" xlink:href="dt-20260930.xsd#dt_DebtInstrumentNumberOfOptionalExtensions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_01a11f2b-c7c7-7829-a769-266e0e31129d" xlink:to="loc_dt_DebtInstrumentNumberOfOptionalExtensions_01a17e13-502a-7c3b-aee9-d01232eb7408" xlink:type="arc" order="28"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_DebtInstrumentOptionalExtensionPeriod_01a17e14-9f10-74ae-9c95-f13f27544cae" xlink:href="dt-20260930.xsd#dt_DebtInstrumentOptionalExtensionPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_01a11f2b-c7c7-7829-a769-266e0e31129d" xlink:to="loc_dt_DebtInstrumentOptionalExtensionPeriod_01a17e14-9f10-74ae-9c95-f13f27544cae" xlink:type="arc" order="29"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_DebtInstrumentConvertibleNotesPrincipalThresholdForEarlyMaturity_01a11f2c-337f-7097-8f5a-e998f9114f5f" xlink:href="dt-20260930.xsd#dt_DebtInstrumentConvertibleNotesPrincipalThresholdForEarlyMaturity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_01a11f2b-c7c7-7829-a769-266e0e31129d" xlink:to="loc_dt_DebtInstrumentConvertibleNotesPrincipalThresholdForEarlyMaturity_01a11f2c-337f-7097-8f5a-e998f9114f5f" xlink:type="arc" order="30"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_LineOfCreditFacilityFrontingFeePercentage_01a11f2c-337f-7682-9976-c1f7ade6c0e4" xlink:href="dt-20260930.xsd#dt_LineOfCreditFacilityFrontingFeePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_01a11f2b-c7c7-7829-a769-266e0e31129d" xlink:to="loc_dt_LineOfCreditFacilityFrontingFeePercentage_01a11f2c-337f-7682-9976-c1f7ade6c0e4" xlink:type="arc" order="31"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredFinanceCostsNet_01a11f2c-337f-7beb-99b7-139649b7454f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredFinanceCostsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_01a11f2b-c7c7-7829-a769-266e0e31129d" xlink:to="loc_us-gaap_DeferredFinanceCostsNet_01a11f2c-337f-7beb-99b7-139649b7454f" xlink:type="arc" order="32"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseDebt_01a11f2c-337f-7382-bf07-30f668ae73d7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestExpenseDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_01a11f2b-c7c7-7829-a769-266e0e31129d" xlink:to="loc_us-gaap_InterestExpenseDebt_01a11f2c-337f-7382-bf07-30f668ae73d7" xlink:type="arc" order="33"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.dynatrace.com/role/LongtermDebtScheduleofCarryingValuesandEstimatedFairValuesofDebtInstrumentsDetails" xlink:type="simple" xlink:href="dt-20260930.xsd#LongtermDebtScheduleofCarryingValuesandEstimatedFairValuesofDebtInstrumentsDetails"/>
  <link:definitionLink xlink:role="http://www.dynatrace.com/role/LongtermDebtScheduleofCarryingValuesandEstimatedFairValuesofDebtInstrumentsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityLineItems_01a143ae-366f-73ea-b449-fe5a118542dc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditFacilityLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityTable_01a143ae-366f-7445-a73a-333a71edaece" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditFacilityTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_01a143ae-366f-73ea-b449-fe5a118542dc" xlink:to="loc_us-gaap_LineOfCreditFacilityTable_01a143ae-366f-7445-a73a-333a71edaece" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_01a143ae-366f-7962-a36c-4978fa73e66b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_01a143ae-366f-7445-a73a-333a71edaece" xlink:to="loc_us-gaap_DebtInstrumentAxis_01a143ae-366f-7962-a36c-4978fa73e66b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_01a143ae-366f-7962-a36c-4978fa73e66b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_01a143ae-366f-7962-a36c-4978fa73e66b" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_01a143ae-366f-7962-a36c-4978fa73e66b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_01a143ae-366f-7791-b583-6b56b8c20e6d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_01a143ae-366f-7962-a36c-4978fa73e66b" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_01a143ae-366f-7791-b583-6b56b8c20e6d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_A2031NotesMember_01a143ae-366f-79d3-a3b4-3d125288f18b" xlink:href="dt-20260930.xsd#dt_A2031NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a143ae-366f-7791-b583-6b56b8c20e6d" xlink:to="loc_dt_A2031NotesMember_01a143ae-366f-79d3-a3b4-3d125288f18b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_01a143ae-366f-78fb-8f0f-3e966b58126b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_01a143ae-366f-7445-a73a-333a71edaece" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_01a143ae-366f-78fb-8f0f-3e966b58126b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_01a143ae-366f-78fb-8f0f-3e966b58126b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_01a143ae-366f-78fb-8f0f-3e966b58126b" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_01a143ae-366f-78fb-8f0f-3e966b58126b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_01a143ae-366f-7846-a847-b6b8d6989631" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_01a143ae-366f-78fb-8f0f-3e966b58126b" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_01a143ae-366f-7846-a847-b6b8d6989631" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConvertibleDebtMember_01a143ae-366f-78e9-ba9c-c8a875de437b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConvertibleDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_01a143ae-366f-7846-a847-b6b8d6989631" xlink:to="loc_us-gaap_ConvertibleDebtMember_01a143ae-366f-78e9-ba9c-c8a875de437b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_01a143ae-366f-72da-af44-6382245eef6c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_01a143ae-366f-73ea-b449-fe5a118542dc" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_01a143ae-366f-72da-af44-6382245eef6c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredFinanceCostsNet_01a143ae-366f-78fe-93ef-cb765821ef75" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredFinanceCostsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_01a143ae-366f-73ea-b449-fe5a118542dc" xlink:to="loc_us-gaap_DeferredFinanceCostsNet_01a143ae-366f-78fe-93ef-cb765821ef75" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_01a154fa-de64-7f83-b1ea-ac528abcf234" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_01a143ae-366f-73ea-b449-fe5a118542dc" xlink:to="loc_us-gaap_LongTermDebt_01a154fa-de64-7f83-b1ea-ac528abcf234" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFairValue_01a143ae-366f-7070-9739-da7b132cc239" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_01a143ae-366f-73ea-b449-fe5a118542dc" xlink:to="loc_us-gaap_DebtInstrumentFairValue_01a143ae-366f-7070-9739-da7b132cc239" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.dynatrace.com/role/ShareholdersEquityDetails" xlink:type="simple" xlink:href="dt-20260930.xsd#ShareholdersEquityDetails"/>
  <link:definitionLink xlink:role="http://www.dynatrace.com/role/ShareholdersEquityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_srt_ShareRepurchaseProgramLineItems_019ff0f8-776b-7360-8d68-21b508c2e82c" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ShareRepurchaseProgramLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ShareRepurchaseProgramTable_019ff0f8-776b-7603-9c03-4452b3ce180e" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ShareRepurchaseProgramTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_srt_ShareRepurchaseProgramLineItems_019ff0f8-776b-7360-8d68-21b508c2e82c" xlink:to="loc_srt_ShareRepurchaseProgramTable_019ff0f8-776b-7603-9c03-4452b3ce180e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ShareRepurchaseProgramAxis_019ff0f8-776b-72f0-982b-c1b9e6dc286b" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ShareRepurchaseProgramAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_srt_ShareRepurchaseProgramTable_019ff0f8-776b-7603-9c03-4452b3ce180e" xlink:to="loc_srt_ShareRepurchaseProgramAxis_019ff0f8-776b-72f0-982b-c1b9e6dc286b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ShareRepurchaseProgramDomain_019ff0f8-776b-72f0-982b-c1b9e6dc286b_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ShareRepurchaseProgramDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ShareRepurchaseProgramAxis_019ff0f8-776b-72f0-982b-c1b9e6dc286b" xlink:to="loc_srt_ShareRepurchaseProgramDomain_019ff0f8-776b-72f0-982b-c1b9e6dc286b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ShareRepurchaseProgramDomain_019ff0f8-776b-77c8-8404-2a418c173851" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ShareRepurchaseProgramDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ShareRepurchaseProgramAxis_019ff0f8-776b-72f0-982b-c1b9e6dc286b" xlink:to="loc_srt_ShareRepurchaseProgramDomain_019ff0f8-776b-77c8-8404-2a418c173851" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_A2024ShareRepurchaseProgramMember_019ff0f8-776b-71f1-9e23-876bed5cba5d" xlink:href="dt-20260930.xsd#dt_A2024ShareRepurchaseProgramMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ShareRepurchaseProgramDomain_019ff0f8-776b-77c8-8404-2a418c173851" xlink:to="loc_dt_A2024ShareRepurchaseProgramMember_019ff0f8-776b-71f1-9e23-876bed5cba5d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_February2026ShareRepurchaseProgramMember_019ff0f8-776b-71f6-bd17-969141dee00f" xlink:href="dt-20260930.xsd#dt_February2026ShareRepurchaseProgramMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ShareRepurchaseProgramDomain_019ff0f8-776b-77c8-8404-2a418c173851" xlink:to="loc_dt_February2026ShareRepurchaseProgramMember_019ff0f8-776b-71f6-bd17-969141dee00f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_November2026ShareRepurchaseProgramMember_01a17a1a-f8bd-7f9a-a2aa-ff41c19bfd79" xlink:href="dt-20260930.xsd#dt_November2026ShareRepurchaseProgramMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ShareRepurchaseProgramDomain_019ff0f8-776b-77c8-8404-2a418c173851" xlink:to="loc_dt_November2026ShareRepurchaseProgramMember_01a17a1a-f8bd-7f9a-a2aa-ff41c19bfd79" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_01a17a1b-573c-7480-9337-eb914e35c571" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_srt_ShareRepurchaseProgramTable_019ff0f8-776b-7603-9c03-4452b3ce180e" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_01a17a1b-573c-7480-9337-eb914e35c571" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_01a17a1b-573c-7480-9337-eb914e35c571_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_01a17a1b-573c-7480-9337-eb914e35c571" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_01a17a1b-573c-7480-9337-eb914e35c571_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_01a17a1b-573c-7d50-94b1-984af76fbcb6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_01a17a1b-573c-7480-9337-eb914e35c571" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_01a17a1b-573c-7d50-94b1-984af76fbcb6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_01a17a1b-6b2e-7973-9a1f-25c2caec8069" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_01a17a1b-573c-7d50-94b1-984af76fbcb6" xlink:to="loc_us-gaap_SubsequentEventMember_01a17a1b-6b2e-7973-9a1f-25c2caec8069" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StockRepurchaseProgramAuthorizedAmount1_019ff0f8-776b-7602-95df-fa79488ebd3f" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_StockRepurchaseProgramAuthorizedAmount1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ShareRepurchaseProgramLineItems_019ff0f8-776b-7360-8d68-21b508c2e82c" xlink:to="loc_srt_StockRepurchaseProgramAuthorizedAmount1_019ff0f8-776b-7602-95df-fa79488ebd3f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_019ff0f8-776b-7809-91c5-62e40ea55fe2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ShareRepurchaseProgramLineItems_019ff0f8-776b-7360-8d68-21b508c2e82c" xlink:to="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_019ff0f8-776b-7809-91c5-62e40ea55fe2" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.dynatrace.com/role/SharebasedCompensationScheduleofCompensationExpenseDetails" xlink:type="simple" xlink:href="dt-20260930.xsd#SharebasedCompensationScheduleofCompensationExpenseDetails"/>
  <link:definitionLink xlink:role="http://www.dynatrace.com/role/SharebasedCompensationScheduleofCompensationExpenseDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_019ff0f8-776b-7fab-83ae-40b6ccf9454c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_019ff0f8-776b-7909-a50d-ec4445cfc38b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_019ff0f8-776b-7fab-83ae-40b6ccf9454c" xlink:to="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_019ff0f8-776b-7909-a50d-ec4445cfc38b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementOfIncomeLocationBalanceAxis_019ff0f8-776b-74eb-beeb-8163b0094749" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementOfIncomeLocationBalanceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_019ff0f8-776b-7909-a50d-ec4445cfc38b" xlink:to="loc_us-gaap_StatementOfIncomeLocationBalanceAxis_019ff0f8-776b-74eb-beeb-8163b0094749" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_019ff0f8-776b-757c-b47a-bfd61c89b1c1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_019ff0f8-776b-7fab-83ae-40b6ccf9454c" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_019ff0f8-776b-757c-b47a-bfd61c89b1c1" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.dynatrace.com/role/SharebasedCompensationScheduleofCompensationExpenseDetails_1" xlink:type="simple" xlink:href="dt-20260930.xsd#SharebasedCompensationScheduleofCompensationExpenseDetails_1"/>
  <link:definitionLink xlink:role="http://www.dynatrace.com/role/SharebasedCompensationScheduleofCompensationExpenseDetails_1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_019ff0f8-776b-7fab-83ae-40b6ccf9454c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_019ff0f8-776b-7909-a50d-ec4445cfc38b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_019ff0f8-776b-7fab-83ae-40b6ccf9454c" xlink:to="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_019ff0f8-776b-7909-a50d-ec4445cfc38b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_019ff0f8-776b-757c-b47a-bfd61c89b1c1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_019ff0f8-776b-7fab-83ae-40b6ccf9454c" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_019ff0f8-776b-757c-b47a-bfd61c89b1c1" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.dynatrace.com/role/SharebasedCompensationNarrativeDetails" xlink:type="simple" xlink:href="dt-20260930.xsd#SharebasedCompensationNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.dynatrace.com/role/SharebasedCompensationNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019ff0f8-776b-7b56-a156-f1431bef6e49" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019ff0f8-776b-7e83-b9d5-b4f9f244ff07" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019ff0f8-776b-7b56-a156-f1431bef6e49" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019ff0f8-776b-7e83-b9d5-b4f9f244ff07" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis_019ff0f8-776b-7231-9748-94e9d2ce7a9d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PlanNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019ff0f8-776b-7e83-b9d5-b4f9f244ff07" xlink:to="loc_us-gaap_PlanNameAxis_019ff0f8-776b-7231-9748-94e9d2ce7a9d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_019ff0f8-776b-7231-9748-94e9d2ce7a9d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_019ff0f8-776b-7231-9748-94e9d2ce7a9d" xlink:to="loc_us-gaap_PlanNameDomain_019ff0f8-776b-7231-9748-94e9d2ce7a9d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_019ff0f8-776b-7321-9693-60f735f13309" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_019ff0f8-776b-7231-9748-94e9d2ce7a9d" xlink:to="loc_us-gaap_PlanNameDomain_019ff0f8-776b-7321-9693-60f735f13309" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_A2019EquityIncentivePlanMember_019ff0f8-776b-7e7b-a668-cb4c4345ac6a" xlink:href="dt-20260930.xsd#dt_A2019EquityIncentivePlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_019ff0f8-776b-7321-9693-60f735f13309" xlink:to="loc_dt_A2019EquityIncentivePlanMember_019ff0f8-776b-7e7b-a668-cb4c4345ac6a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_A2019EmployeeStockPurchasePlanMember_019ff0f8-776b-70b9-ae95-3bde7ea4abee" xlink:href="dt-20260930.xsd#dt_A2019EmployeeStockPurchasePlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_019ff0f8-776b-7321-9693-60f735f13309" xlink:to="loc_dt_A2019EmployeeStockPurchasePlanMember_019ff0f8-776b-70b9-ae95-3bde7ea4abee" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019ff0f8-776b-7d37-98a5-7cf784e61ee4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019ff0f8-776b-7e83-b9d5-b4f9f244ff07" xlink:to="loc_us-gaap_AwardTypeAxis_019ff0f8-776b-7d37-98a5-7cf784e61ee4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ff0f8-776b-7d37-98a5-7cf784e61ee4_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_019ff0f8-776b-7d37-98a5-7cf784e61ee4" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ff0f8-776b-7d37-98a5-7cf784e61ee4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ff0f8-776b-7f9c-88da-27557ea724d2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_019ff0f8-776b-7d37-98a5-7cf784e61ee4" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ff0f8-776b-7f9c-88da-27557ea724d2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_RestrictedStockUnitsRSUsServiceBasedMember_019ff0f8-776b-7855-a641-724f70112b05" xlink:href="dt-20260930.xsd#dt_RestrictedStockUnitsRSUsServiceBasedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ff0f8-776b-7f9c-88da-27557ea724d2" xlink:to="loc_dt_RestrictedStockUnitsRSUsServiceBasedMember_019ff0f8-776b-7855-a641-724f70112b05" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_RestrictedStockUnitsRSUsServiceAndPerformanceBasedMember_019ff0f8-776b-7e35-9254-abb7165b26c1" xlink:href="dt-20260930.xsd#dt_RestrictedStockUnitsRSUsServiceAndPerformanceBasedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ff0f8-776b-7f9c-88da-27557ea724d2" xlink:to="loc_dt_RestrictedStockUnitsRSUsServiceAndPerformanceBasedMember_019ff0f8-776b-7e35-9254-abb7165b26c1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_RestrictedStockUnitsRSUsServiceAndPerformanceBasedFinancialPerformanceConditionsMember_019ff0f8-776b-7212-afe3-3cc97487dadc" xlink:href="dt-20260930.xsd#dt_RestrictedStockUnitsRSUsServiceAndPerformanceBasedFinancialPerformanceConditionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dt_RestrictedStockUnitsRSUsServiceAndPerformanceBasedMember_019ff0f8-776b-7e35-9254-abb7165b26c1" xlink:to="loc_dt_RestrictedStockUnitsRSUsServiceAndPerformanceBasedFinancialPerformanceConditionsMember_019ff0f8-776b-7212-afe3-3cc97487dadc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_RestrictedStockUnitsRSUsServiceAndPerformanceBasedRelativeTotalStockholderReturnPerformanceMember_019ff0f8-776b-7859-bc30-4ba941c36c2f" xlink:href="dt-20260930.xsd#dt_RestrictedStockUnitsRSUsServiceAndPerformanceBasedRelativeTotalStockholderReturnPerformanceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dt_RestrictedStockUnitsRSUsServiceAndPerformanceBasedMember_019ff0f8-776b-7e35-9254-abb7165b26c1" xlink:to="loc_dt_RestrictedStockUnitsRSUsServiceAndPerformanceBasedRelativeTotalStockholderReturnPerformanceMember_019ff0f8-776b-7859-bc30-4ba941c36c2f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_019ff0f8-776b-7b30-a1ca-9a2196f06826" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ff0f8-776b-7f9c-88da-27557ea724d2" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_019ff0f8-776b-7b30-a1ca-9a2196f06826" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_019ff0f8-776b-73c7-9bf1-a9f503661a17" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ff0f8-776b-7f9c-88da-27557ea724d2" xlink:to="loc_us-gaap_RestrictedStockMember_019ff0f8-776b-73c7-9bf1-a9f503661a17" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockMember_019ff0f8-776b-733a-8b6b-1f6f76e72eba" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ff0f8-776b-7f9c-88da-27557ea724d2" xlink:to="loc_us-gaap_EmployeeStockMember_019ff0f8-776b-733a-8b6b-1f6f76e72eba" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VestingAxis_019ff0f8-776b-742b-a6a5-8a47f6d71fcc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_VestingAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019ff0f8-776b-7e83-b9d5-b4f9f244ff07" xlink:to="loc_us-gaap_VestingAxis_019ff0f8-776b-742b-a6a5-8a47f6d71fcc" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VestingDomain_019ff0f8-776b-742b-a6a5-8a47f6d71fcc_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_VestingDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VestingAxis_019ff0f8-776b-742b-a6a5-8a47f6d71fcc" xlink:to="loc_us-gaap_VestingDomain_019ff0f8-776b-742b-a6a5-8a47f6d71fcc_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VestingDomain_019ff0f8-776b-7ed0-93ea-c0c3dd7de12c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_VestingDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VestingAxis_019ff0f8-776b-742b-a6a5-8a47f6d71fcc" xlink:to="loc_us-gaap_VestingDomain_019ff0f8-776b-7ed0-93ea-c0c3dd7de12c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationAwardTrancheOneMember_019ff0f8-776b-7139-9a91-f7d2b468b3f2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationAwardTrancheOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VestingDomain_019ff0f8-776b-7ed0-93ea-c0c3dd7de12c" xlink:to="loc_us-gaap_ShareBasedCompensationAwardTrancheOneMember_019ff0f8-776b-7139-9a91-f7d2b468b3f2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationAwardTrancheTwoMember_019ff0f8-776b-7589-b359-341ee94ab0ba" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationAwardTrancheTwoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VestingDomain_019ff0f8-776b-7ed0-93ea-c0c3dd7de12c" xlink:to="loc_us-gaap_ShareBasedCompensationAwardTrancheTwoMember_019ff0f8-776b-7589-b359-341ee94ab0ba" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_019ff0f8-776b-7392-a0f4-96f554e91537" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019ff0f8-776b-7e83-b9d5-b4f9f244ff07" xlink:to="loc_us-gaap_StatementClassOfStockAxis_019ff0f8-776b-7392-a0f4-96f554e91537" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019ff0f8-776b-7392-a0f4-96f554e91537_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019ff0f8-776b-7392-a0f4-96f554e91537" xlink:to="loc_us-gaap_ClassOfStockDomain_019ff0f8-776b-7392-a0f4-96f554e91537_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019ff0f8-776b-75c6-8d4b-0091c45d338f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019ff0f8-776b-7392-a0f4-96f554e91537" xlink:to="loc_us-gaap_ClassOfStockDomain_019ff0f8-776b-75c6-8d4b-0091c45d338f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_019ff0f8-776b-7433-8523-f2c38310fc73" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019ff0f8-776b-75c6-8d4b-0091c45d338f" xlink:to="loc_us-gaap_CommonClassAMember_019ff0f8-776b-7433-8523-f2c38310fc73" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_019ff0f8-776b-7b8b-95b2-7d530e72501f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockCapitalSharesReservedForFutureIssuance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019ff0f8-776b-7b56-a156-f1431bef6e49" xlink:to="loc_us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_019ff0f8-776b-7b8b-95b2-7d530e72501f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_CommonStockCapitalSharesReservedForFutureIssuanceAnnualPercentageIncrease_019ff0f8-776b-705e-b42c-99285d609c5a" xlink:href="dt-20260930.xsd#dt_CommonStockCapitalSharesReservedForFutureIssuanceAnnualPercentageIncrease"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019ff0f8-776b-7b56-a156-f1431bef6e49" xlink:to="loc_dt_CommonStockCapitalSharesReservedForFutureIssuanceAnnualPercentageIncrease_019ff0f8-776b-705e-b42c-99285d609c5a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019ff0f8-776b-7674-a440-d51c57fc153d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019ff0f8-776b-7b56-a156-f1431bef6e49" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019ff0f8-776b-7674-a440-d51c57fc153d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumPercentageOfSharesIssuedBasedOnPerformanceTargetAward_019ff0f8-776b-7fe4-aeda-cd7af5350b25" xlink:href="dt-20260930.xsd#dt_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumPercentageOfSharesIssuedBasedOnPerformanceTargetAward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019ff0f8-776b-7b56-a156-f1431bef6e49" xlink:to="loc_dt_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumPercentageOfSharesIssuedBasedOnPerformanceTargetAward_019ff0f8-776b-7fe4-aeda-cd7af5350b25" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage_019ff0f8-776b-7b1d-861b-e7ccd0b271ec" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019ff0f8-776b-7b56-a156-f1431bef6e49" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage_019ff0f8-776b-7b1d-861b-e7ccd0b271ec" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_019ff0f8-776b-758e-a8e3-b885d06f4d6f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019ff0f8-776b-7b56-a156-f1431bef6e49" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_019ff0f8-776b-758e-a8e3-b885d06f4d6f" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_019ff0f8-776b-76c7-a14b-bd8d72ab368a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019ff0f8-776b-7b56-a156-f1431bef6e49" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_019ff0f8-776b-76c7-a14b-bd8d72ab368a" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_019ff0f8-776b-7708-b6bc-a006e8fff1b2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019ff0f8-776b-7b56-a156-f1431bef6e49" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_019ff0f8-776b-7708-b6bc-a006e8fff1b2" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_019ff0f8-776b-7b2f-b8ad-0f4b22d47558" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019ff0f8-776b-7b56-a156-f1431bef6e49" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_019ff0f8-776b-7b2f-b8ad-0f4b22d47558" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions_019ff0f8-776b-7ca4-96d7-a198cd6d8a72" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019ff0f8-776b-7b56-a156-f1431bef6e49" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions_019ff0f8-776b-7ca4-96d7-a198cd6d8a72" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_ShareBasedCompensationArrangementByShareBasedPaymentAwardStockPlanOfferingPeriod_019ff0f8-776b-734c-904d-08295db08382" xlink:href="dt-20260930.xsd#dt_ShareBasedCompensationArrangementByShareBasedPaymentAwardStockPlanOfferingPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019ff0f8-776b-7b56-a156-f1431bef6e49" xlink:to="loc_dt_ShareBasedCompensationArrangementByShareBasedPaymentAwardStockPlanOfferingPeriod_019ff0f8-776b-734c-904d-08295db08382" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_ShareBasedCompensationArrangementByShareBasedPaymentAwardStockPlanPurchasePeriod_019ff0f8-776b-73c8-af5d-ddcc42554e0f" xlink:href="dt-20260930.xsd#dt_ShareBasedCompensationArrangementByShareBasedPaymentAwardStockPlanPurchasePeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019ff0f8-776b-7b56-a156-f1431bef6e49" xlink:to="loc_dt_ShareBasedCompensationArrangementByShareBasedPaymentAwardStockPlanPurchasePeriod_019ff0f8-776b-73c8-af5d-ddcc42554e0f" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardPurchasePriceOfCommonStockPercent_019ff0f8-776b-714c-ad36-466ba5ebee4a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardPurchasePriceOfCommonStockPercent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019ff0f8-776b-7b56-a156-f1431bef6e49" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardPurchasePriceOfCommonStockPercent_019ff0f8-776b-714c-ad36-466ba5ebee4a" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans_019ff0f8-776b-7d3a-b0ae-0bf0c21df3c3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019ff0f8-776b-7b56-a156-f1431bef6e49" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans_019ff0f8-776b-7d3a-b0ae-0bf0c21df3c3" xlink:type="arc" order="13"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.dynatrace.com/role/SharebasedCompensationScheduleofRestrictedStockActivityDetails" xlink:type="simple" xlink:href="dt-20260930.xsd#SharebasedCompensationScheduleofRestrictedStockActivityDetails"/>
  <link:definitionLink xlink:role="http://www.dynatrace.com/role/SharebasedCompensationScheduleofRestrictedStockActivityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019ff0f8-776b-7b21-979d-80c03822b3b0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019ff0f8-776b-73d0-a252-52e11a1797e4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019ff0f8-776b-7b21-979d-80c03822b3b0" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019ff0f8-776b-73d0-a252-52e11a1797e4" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019ff0f8-776b-7637-84c3-8d7c4f730c67" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019ff0f8-776b-73d0-a252-52e11a1797e4" xlink:to="loc_us-gaap_AwardTypeAxis_019ff0f8-776b-7637-84c3-8d7c4f730c67" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ff0f8-776b-7637-84c3-8d7c4f730c67_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_019ff0f8-776b-7637-84c3-8d7c4f730c67" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ff0f8-776b-7637-84c3-8d7c4f730c67_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ff0f8-776b-7858-ace6-36948a304a03" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_019ff0f8-776b-7637-84c3-8d7c4f730c67" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ff0f8-776b-7858-ace6-36948a304a03" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_019ff0f8-776b-71bd-a2e4-19ac3956aa91" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ff0f8-776b-7858-ace6-36948a304a03" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_019ff0f8-776b-71bd-a2e4-19ac3956aa91" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_019ff0f8-776b-7c6f-86b5-56587978cf55" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ff0f8-776b-7858-ace6-36948a304a03" xlink:to="loc_us-gaap_RestrictedStockMember_019ff0f8-776b-7c6f-86b5-56587978cf55" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019ff0f8-776b-7c41-8874-c06cf69da3eb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019ff0f8-776b-7b21-979d-80c03822b3b0" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019ff0f8-776b-7c41-8874-c06cf69da3eb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019ff0f8-776b-7f93-a266-d1ba5d7da3ee" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019ff0f8-776b-7c41-8874-c06cf69da3eb" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019ff0f8-776b-7f93-a266-d1ba5d7da3ee" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_019ff0f8-776b-751f-9ec8-2909c1a73ffa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019ff0f8-776b-7c41-8874-c06cf69da3eb" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_019ff0f8-776b-751f-9ec8-2909c1a73ffa" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_019ff0f8-776b-781d-9a17-28f44f8e7d23" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019ff0f8-776b-7c41-8874-c06cf69da3eb" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_019ff0f8-776b-781d-9a17-28f44f8e7d23" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_019ff0f8-776b-720f-bcbd-71fad1120b4f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019ff0f8-776b-7c41-8874-c06cf69da3eb" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_019ff0f8-776b-720f-bcbd-71fad1120b4f" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019ff0f8-776b-719f-bfe7-743f79f32689" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019ff0f8-776b-7fc2-8862-60995af0f353" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019ff0f8-776b-7b21-979d-80c03822b3b0" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019ff0f8-776b-7fc2-8862-60995af0f353" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019ff0f8-776b-7829-8e64-719368f45793" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019ff0f8-776b-7fc2-8862-60995af0f353" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019ff0f8-776b-7829-8e64-719368f45793" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_019ff0f8-776b-7f5e-9f52-a43845472ac9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019ff0f8-776b-7fc2-8862-60995af0f353" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_019ff0f8-776b-7f5e-9f52-a43845472ac9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_019ff0f8-776b-7d03-bf37-b7d5505b3ba9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019ff0f8-776b-7fc2-8862-60995af0f353" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_019ff0f8-776b-7d03-bf37-b7d5505b3ba9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_019ff0f8-776b-7c49-9416-c3a584961194" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019ff0f8-776b-7fc2-8862-60995af0f353" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_019ff0f8-776b-7c49-9416-c3a584961194" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019ff0f8-776b-7199-b31f-df5a9749340d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.dynatrace.com/role/NetIncomePerShareScheduleofWeightedAverageAntidilutiveCommonShareDetails" xlink:type="simple" xlink:href="dt-20260930.xsd#NetIncomePerShareScheduleofWeightedAverageAntidilutiveCommonShareDetails"/>
  <link:definitionLink xlink:role="http://www.dynatrace.com/role/NetIncomePerShareScheduleofWeightedAverageAntidilutiveCommonShareDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_019ff0f8-776b-79c2-84fa-ab0e3c94ee72" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_019ff0f8-776b-7cb2-82b8-c8f5f415559b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_019ff0f8-776b-79c2-84fa-ab0e3c94ee72" xlink:to="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_019ff0f8-776b-7cb2-82b8-c8f5f415559b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_019ff0f8-776b-7620-957d-14ea7024a11e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_019ff0f8-776b-7cb2-82b8-c8f5f415559b" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_019ff0f8-776b-7620-957d-14ea7024a11e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019ff0f8-776b-7620-957d-14ea7024a11e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_019ff0f8-776b-7620-957d-14ea7024a11e" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019ff0f8-776b-7620-957d-14ea7024a11e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019ff0f8-776b-7443-915c-89b3bfa42481" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_019ff0f8-776b-7620-957d-14ea7024a11e" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019ff0f8-776b-7443-915c-89b3bfa42481" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_RestrictedStockAndRestrictedStockUnitsMember_019ff0f8-776b-7069-bf0f-2b6793e422ee" xlink:href="dt-20260930.xsd#dt_RestrictedStockAndRestrictedStockUnitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019ff0f8-776b-7443-915c-89b3bfa42481" xlink:to="loc_dt_RestrictedStockAndRestrictedStockUnitsMember_019ff0f8-776b-7069-bf0f-2b6793e422ee" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_019ff0f8-776b-74a9-982f-33e5405ccc89" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019ff0f8-776b-7443-915c-89b3bfa42481" xlink:to="loc_us-gaap_EmployeeStockOptionMember_019ff0f8-776b-74a9-982f-33e5405ccc89" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockMember_019ff0f8-776b-72f5-be68-ce27b304e0a6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019ff0f8-776b-7443-915c-89b3bfa42481" xlink:to="loc_us-gaap_EmployeeStockMember_019ff0f8-776b-72f5-be68-ce27b304e0a6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WarrantMember_01a143cf-d28b-7234-8851-7171a808ea0c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WarrantMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019ff0f8-776b-7443-915c-89b3bfa42481" xlink:to="loc_us-gaap_WarrantMember_01a143cf-d28b-7234-8851-7171a808ea0c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_019ff0f8-776b-7911-90a8-b38a3335bbd4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_019ff0f8-776b-79c2-84fa-ab0e3c94ee72" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_019ff0f8-776b-7911-90a8-b38a3335bbd4" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.dynatrace.com/role/SegmentandGeographicInformationScheduleofSegmentReportingInformationbySegmentDetails" xlink:type="simple" xlink:href="dt-20260930.xsd#SegmentandGeographicInformationScheduleofSegmentReportingInformationbySegmentDetails"/>
  <link:definitionLink xlink:role="http://www.dynatrace.com/role/SegmentandGeographicInformationScheduleofSegmentReportingInformationbySegmentDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_019ff0f8-776b-77cd-99ab-07036c9f326e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_019ff0f8-776b-7929-8042-e081a2fe86b1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_019ff0f8-776b-77cd-99ab-07036c9f326e" xlink:to="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_019ff0f8-776b-7929-8042-e081a2fe86b1" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019ff0f8-776b-7dd5-be01-e27b23f9ff0e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_019ff0f8-776b-7929-8042-e081a2fe86b1" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019ff0f8-776b-7dd5-be01-e27b23f9ff0e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019ff0f8-776b-7dd5-be01-e27b23f9ff0e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019ff0f8-776b-7dd5-be01-e27b23f9ff0e" xlink:to="loc_us-gaap_SegmentDomain_019ff0f8-776b-7dd5-be01-e27b23f9ff0e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019ff0f8-776b-71bf-ab1d-eb6ec055740e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019ff0f8-776b-7dd5-be01-e27b23f9ff0e" xlink:to="loc_us-gaap_SegmentDomain_019ff0f8-776b-71bf-ab1d-eb6ec055740e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_ReportableSegmentMember_019ff0f8-776b-7cb8-92b2-47bb3e8c805a" xlink:href="dt-20260930.xsd#dt_ReportableSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019ff0f8-776b-71bf-ab1d-eb6ec055740e" xlink:to="loc_dt_ReportableSegmentMember_019ff0f8-776b-7cb8-92b2-47bb3e8c805a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019ff0f8-776b-707a-9165-b4d96e20b999" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_019ff0f8-776b-77cd-99ab-07036c9f326e" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019ff0f8-776b-707a-9165-b4d96e20b999" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_AdjustedCostOfRevenue_019ff0f8-776b-7fab-8ae1-9ce4b6f67c33" xlink:href="dt-20260930.xsd#dt_AdjustedCostOfRevenue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_019ff0f8-776b-77cd-99ab-07036c9f326e" xlink:to="loc_dt_AdjustedCostOfRevenue_019ff0f8-776b-7fab-8ae1-9ce4b6f67c33" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_AdjustedResearchAndDevelopmentExpenses_019ff0f8-776b-742c-8f08-ed1c08672f9b" xlink:href="dt-20260930.xsd#dt_AdjustedResearchAndDevelopmentExpenses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_019ff0f8-776b-77cd-99ab-07036c9f326e" xlink:to="loc_dt_AdjustedResearchAndDevelopmentExpenses_019ff0f8-776b-742c-8f08-ed1c08672f9b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_AdjustedSalesAndMarketingExpenses_019ff0f8-776b-71ed-a2df-0bd8890605d3" xlink:href="dt-20260930.xsd#dt_AdjustedSalesAndMarketingExpenses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_019ff0f8-776b-77cd-99ab-07036c9f326e" xlink:to="loc_dt_AdjustedSalesAndMarketingExpenses_019ff0f8-776b-71ed-a2df-0bd8890605d3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_AdjustedGeneralAndAdministrativeExpenses_019ff0f8-776b-7115-9853-9dc451e75f21" xlink:href="dt-20260930.xsd#dt_AdjustedGeneralAndAdministrativeExpenses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_019ff0f8-776b-77cd-99ab-07036c9f326e" xlink:to="loc_dt_AdjustedGeneralAndAdministrativeExpenses_019ff0f8-776b-7115-9853-9dc451e75f21" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_ShareBasedCompensationAndRelatedEmployerPayrollTaxes_019ff0f8-776b-7407-8f43-3fb1a5a689c7" xlink:href="dt-20260930.xsd#dt_ShareBasedCompensationAndRelatedEmployerPayrollTaxes"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_019ff0f8-776b-77cd-99ab-07036c9f326e" xlink:to="loc_dt_ShareBasedCompensationAndRelatedEmployerPayrollTaxes_019ff0f8-776b-7407-8f43-3fb1a5a689c7" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_019ff0f8-776b-7a29-b7ef-8c5f473119f2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AmortizationOfIntangibleAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_019ff0f8-776b-77cd-99ab-07036c9f326e" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_019ff0f8-776b-7a29-b7ef-8c5f473119f2" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingOtherItemAmount_019ff0f8-776b-728a-ae8f-75da15ac1a76" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentReportingOtherItemAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_019ff0f8-776b-77cd-99ab-07036c9f326e" xlink:to="loc_us-gaap_SegmentReportingOtherItemAmount_019ff0f8-776b-728a-ae8f-75da15ac1a76" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019ff0f8-776b-78e0-91e3-6b50e1250704" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_019ff0f8-776b-77cd-99ab-07036c9f326e" xlink:to="loc_us-gaap_NetIncomeLoss_019ff0f8-776b-78e0-91e3-6b50e1250704" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_SegmentReportingOtherSegmentItemAmountOther_019ff0f8-776c-703e-a96b-e5dd4e7b171b" xlink:href="dt-20260930.xsd#dt_SegmentReportingOtherSegmentItemAmountOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_019ff0f8-776b-77cd-99ab-07036c9f326e" xlink:to="loc_dt_SegmentReportingOtherSegmentItemAmountOther_019ff0f8-776c-703e-a96b-e5dd4e7b171b" xlink:type="arc" order="9"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.dynatrace.com/role/SegmentandGeographicInformationScheduleofLonglivedAssetsbyGeographicalRegionDetails" xlink:type="simple" xlink:href="dt-20260930.xsd#SegmentandGeographicInformationScheduleofLonglivedAssetsbyGeographicalRegionDetails"/>
  <link:definitionLink xlink:role="http://www.dynatrace.com/role/SegmentandGeographicInformationScheduleofLonglivedAssetsbyGeographicalRegionDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_019ff0f8-776c-738e-bf24-f7c38da43ffe" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_019ff0f8-776c-7570-8590-dcb4e0c2666f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_019ff0f8-776c-738e-bf24-f7c38da43ffe" xlink:to="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_019ff0f8-776c-7570-8590-dcb4e0c2666f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_019ff0f8-776c-7112-9d1a-1a4cea4dc2e5" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_019ff0f8-776c-7570-8590-dcb4e0c2666f" xlink:to="loc_srt_StatementGeographicalAxis_019ff0f8-776c-7112-9d1a-1a4cea4dc2e5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_019ff0f8-776c-7112-9d1a-1a4cea4dc2e5_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_019ff0f8-776c-7112-9d1a-1a4cea4dc2e5" xlink:to="loc_srt_SegmentGeographicalDomain_019ff0f8-776c-7112-9d1a-1a4cea4dc2e5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_019ff0f8-776c-739f-acee-dc9cb5acfdee" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_019ff0f8-776c-7112-9d1a-1a4cea4dc2e5" xlink:to="loc_srt_SegmentGeographicalDomain_019ff0f8-776c-739f-acee-dc9cb5acfdee" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NorthAmericaMember_019ff0f8-776c-7629-8401-056b8d66fcee" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_NorthAmericaMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019ff0f8-776c-739f-acee-dc9cb5acfdee" xlink:to="loc_srt_NorthAmericaMember_019ff0f8-776c-7629-8401-056b8d66fcee" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EMEAMember_019ff0f8-776c-750b-8c36-c86480bcaf04" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EMEAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019ff0f8-776c-739f-acee-dc9cb5acfdee" xlink:to="loc_us-gaap_EMEAMember_019ff0f8-776c-750b-8c36-c86480bcaf04" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AsiaPacificMember_019ff0f8-776c-7161-9026-c0f1a4823012" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_AsiaPacificMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019ff0f8-776c-739f-acee-dc9cb5acfdee" xlink:to="loc_srt_AsiaPacificMember_019ff0f8-776c-7161-9026-c0f1a4823012" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_LatinAmericaMember_019ff0f8-776c-7c23-90a2-51fad6b3898f" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_LatinAmericaMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019ff0f8-776c-739f-acee-dc9cb5acfdee" xlink:to="loc_srt_LatinAmericaMember_019ff0f8-776c-7c23-90a2-51fad6b3898f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncurrentAssets_019ff0f8-776c-7292-8e50-1455d7ef9e05" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NoncurrentAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_019ff0f8-776c-738e-bf24-f7c38da43ffe" xlink:to="loc_us-gaap_NoncurrentAssets_019ff0f8-776c-7292-8e50-1455d7ef9e05" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.dynatrace.com/role/SubsequentEventsDetails" xlink:type="simple" xlink:href="dt-20260930.xsd#SubsequentEventsDetails"/>
  <link:definitionLink xlink:role="http://www.dynatrace.com/role/SubsequentEventsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventLineItems_019ff0f8-776c-7bbe-9aff-65332ccd4db3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTable_019ff0f8-776c-7ce2-aec6-77051e265f2e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SubsequentEventLineItems_019ff0f8-776c-7bbe-9aff-65332ccd4db3" xlink:to="loc_us-gaap_SubsequentEventTable_019ff0f8-776c-7ce2-aec6-77051e265f2e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_019ff0f8-776c-7aa6-955b-5e10d2c71606" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_019ff0f8-776c-7ce2-aec6-77051e265f2e" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_019ff0f8-776c-7aa6-955b-5e10d2c71606" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ff0f8-776c-7aa6-955b-5e10d2c71606_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019ff0f8-776c-7aa6-955b-5e10d2c71606" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ff0f8-776c-7aa6-955b-5e10d2c71606_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ff0f8-776c-7476-8b66-394c498ea19f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019ff0f8-776c-7aa6-955b-5e10d2c71606" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ff0f8-776c-7476-8b66-394c498ea19f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_ArizeMember_01a0c78f-adb8-7301-944c-87c32e4704ca" xlink:href="dt-20260930.xsd#dt_ArizeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ff0f8-776c-7476-8b66-394c498ea19f" xlink:to="loc_dt_ArizeMember_01a0c78f-adb8-7301-944c-87c32e4704ca" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_01a0c95b-f6b0-7069-9661-22761b2f76c7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_019ff0f8-776c-7ce2-aec6-77051e265f2e" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_01a0c95b-f6b0-7069-9661-22761b2f76c7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_01a0c95b-f6b0-7069-9661-22761b2f76c7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_01a0c95b-f6b0-7069-9661-22761b2f76c7" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_01a0c95b-f6b0-7069-9661-22761b2f76c7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_01a0c95b-f6b0-73a3-bfc6-b209fc831fa7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_01a0c95b-f6b0-7069-9661-22761b2f76c7" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_01a0c95b-f6b0-73a3-bfc6-b209fc831fa7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_01a0c95c-14dd-7006-a6b4-0531b7444177" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_01a0c95b-f6b0-73a3-bfc6-b209fc831fa7" xlink:to="loc_us-gaap_SubsequentEventMember_01a0c95c-14dd-7006-a6b4-0531b7444177" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_01a16220-a2ad-732f-a991-3fcdb4ac0871" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_019ff0f8-776c-7ce2-aec6-77051e265f2e" xlink:to="loc_us-gaap_AwardTypeAxis_01a16220-a2ad-732f-a991-3fcdb4ac0871" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a16220-a2ad-732f-a991-3fcdb4ac0871_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_01a16220-a2ad-732f-a991-3fcdb4ac0871" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a16220-a2ad-732f-a991-3fcdb4ac0871_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a16220-a2ad-7954-a4af-d96d4017def8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_01a16220-a2ad-732f-a991-3fcdb4ac0871" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a16220-a2ad-7954-a4af-d96d4017def8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_RestrictedCommonStockAndRestrictedStockUnitsRSUsMember_01a17a1e-003d-7001-841a-45cb6bc777cb" xlink:href="dt-20260930.xsd#dt_RestrictedCommonStockAndRestrictedStockUnitsRSUsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a16220-a2ad-7954-a4af-d96d4017def8" xlink:to="loc_dt_RestrictedCommonStockAndRestrictedStockUnitsRSUsMember_01a17a1e-003d-7001-841a-45cb6bc777cb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_01a16220-a2ad-72db-8cee-b70d89c6f32c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a16220-a2ad-7954-a4af-d96d4017def8" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_01a16220-a2ad-72db-8cee-b70d89c6f32c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ShareRepurchaseProgramAxis_01a17a1c-1951-7247-bc20-8e090c36bf63" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ShareRepurchaseProgramAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_019ff0f8-776c-7ce2-aec6-77051e265f2e" xlink:to="loc_srt_ShareRepurchaseProgramAxis_01a17a1c-1951-7247-bc20-8e090c36bf63" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ShareRepurchaseProgramDomain_01a17a1c-1951-7247-bc20-8e090c36bf63_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ShareRepurchaseProgramDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ShareRepurchaseProgramAxis_01a17a1c-1951-7247-bc20-8e090c36bf63" xlink:to="loc_srt_ShareRepurchaseProgramDomain_01a17a1c-1951-7247-bc20-8e090c36bf63_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ShareRepurchaseProgramDomain_01a17a1c-1951-798e-86c1-7f1c7b704841" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ShareRepurchaseProgramDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ShareRepurchaseProgramAxis_01a17a1c-1951-7247-bc20-8e090c36bf63" xlink:to="loc_srt_ShareRepurchaseProgramDomain_01a17a1c-1951-798e-86c1-7f1c7b704841" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_November2026ShareRepurchaseProgramMember_01a17a1c-1951-750b-aca6-11940b7facd6" xlink:href="dt-20260930.xsd#dt_November2026ShareRepurchaseProgramMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ShareRepurchaseProgramDomain_01a17a1c-1951-798e-86c1-7f1c7b704841" xlink:to="loc_dt_November2026ShareRepurchaseProgramMember_01a17a1c-1951-750b-aca6-11940b7facd6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesGross_01a0c78f-adb8-7930-a08a-923ccb328a9d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsToAcquireBusinessesGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_019ff0f8-776c-7bbe-9aff-65332ccd4db3" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesGross_01a0c78f-adb8-7930-a08a-923ccb328a9d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued_01a16220-a2ad-7899-a5d6-960d1d172bce" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_019ff0f8-776c-7bbe-9aff-65332ccd4db3" xlink:to="loc_us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued_01a16220-a2ad-7899-a5d6-960d1d172bce" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionEquityInterestIssuedOrIssuableValueAssigned_01a16220-a2ad-75e8-80d1-b0539c7f4df0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionEquityInterestIssuedOrIssuableValueAssigned"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_019ff0f8-776c-7bbe-9aff-65332ccd4db3" xlink:to="loc_us-gaap_BusinessAcquisitionEquityInterestIssuedOrIssuableValueAssigned_01a16220-a2ad-75e8-80d1-b0539c7f4df0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodGrantDateFairValue_01a17a20-fd82-79a1-8a11-44bd776f4f17" xlink:href="dt-20260930.xsd#dt_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_019ff0f8-776c-7bbe-9aff-65332ccd4db3" xlink:to="loc_dt_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodGrantDateFairValue_01a17a20-fd82-79a1-8a11-44bd776f4f17" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StockRepurchaseProgramAuthorizedAmount1_01a17a1c-1951-7821-a971-40adc4cae63a" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_StockRepurchaseProgramAuthorizedAmount1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_019ff0f8-776c-7bbe-9aff-65332ccd4db3" xlink:to="loc_srt_StockRepurchaseProgramAuthorizedAmount1_01a17a1c-1951-7821-a971-40adc4cae63a" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://xbrl.sec.gov/ecd/role/IndividualsOnly" xlink:type="simple" xlink:href="https://xbrl.sec.gov/ecd/2026/ecd-2026.xsd#IndividualsOnly"/>
  <link:definitionLink xlink:role="http://xbrl.sec.gov/ecd/role/IndividualsOnly" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_ecd_AllIndividualsMember" xlink:href="https://xbrl.sec.gov/ecd/2026/ecd-2026.xsd#ecd_AllIndividualsMember"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_LisaCampbellMember_019ff0f8-76bf-7861-b126-ec0b84020de3" xlink:href="dt-20260930.xsd#dt_LisaCampbellMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ecd_AllIndividualsMember" xlink:to="loc_dt_LisaCampbellMember_019ff0f8-76bf-7861-b126-ec0b84020de3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dt_DanielZugelderMember_01a11f4d-7271-7a5d-8642-1e9455f259a7" xlink:href="dt-20260930.xsd#dt_DanielZugelderMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ecd_AllIndividualsMember" xlink:to="loc_dt_DanielZugelderMember_01a11f4d-7271-7a5d-8642-1e9455f259a7" xlink:type="arc" order="3"/>
  </link:definitionLink>
</link:linkbase>
