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

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:019f22d0-ea90-7b83-a56f-f2265d9850a7,g:a92d8b44-16d9-494c-9966-2b9fd0750583-->
<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.corp.kaltura.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFOPERATIONS" xlink:type="simple" xlink:href="kltr-20260630.xsd#CONDENSEDCONSOLIDATEDSTATEMENTSOFOPERATIONS"/>
  <link:definitionLink xlink:role="http://www.corp.kaltura.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFOPERATIONS" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_019f22d0-ec66-7ac9-b3c6-5abfbf9abac3" 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_019f22d0-ec66-7e08-ac76-080e7ea5ffb1" 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_019f22d0-ec66-7ac9-b3c6-5abfbf9abac3" xlink:to="loc_us-gaap_StatementTable_019f22d0-ec66-7e08-ac76-080e7ea5ffb1" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_019f22d0-ec66-73ed-b774-99fc4fe59006" 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_019f22d0-ec66-7e08-ac76-080e7ea5ffb1" xlink:to="loc_srt_ProductOrServiceAxis_019f22d0-ec66-73ed-b774-99fc4fe59006" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019f22d0-ec66-73ed-b774-99fc4fe59006_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_019f22d0-ec66-73ed-b774-99fc4fe59006" xlink:to="loc_srt_ProductsAndServicesDomain_019f22d0-ec66-73ed-b774-99fc4fe59006_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019f22d0-ec66-7c2b-8751-f3f666825a6f" 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_019f22d0-ec66-73ed-b774-99fc4fe59006" xlink:to="loc_srt_ProductsAndServicesDomain_019f22d0-ec66-7c2b-8751-f3f666825a6f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_SubscriptionMember_019f22d0-ec66-7ab1-b614-4175f15c9906" xlink:href="kltr-20260630.xsd#kltr_SubscriptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f22d0-ec66-7c2b-8751-f3f666825a6f" xlink:to="loc_kltr_SubscriptionMember_019f22d0-ec66-7ab1-b614-4175f15c9906" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_ProfessionalServicesMember_019f22d0-ec66-71b8-8a76-952911c9ea51" xlink:href="kltr-20260630.xsd#kltr_ProfessionalServicesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f22d0-ec66-7c2b-8751-f3f666825a6f" xlink:to="loc_kltr_ProfessionalServicesMember_019f22d0-ec66-71b8-8a76-952911c9ea51" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenuesAbstract_019f22d0-ec66-74f5-aa47-9b0397cdfade" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenuesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019f22d0-ec66-7ac9-b3c6-5abfbf9abac3" xlink:to="loc_us-gaap_RevenuesAbstract_019f22d0-ec66-74f5-aa47-9b0397cdfade" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019f22d0-ec66-796f-bb3c-e05567c402d8" 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_RevenuesAbstract_019f22d0-ec66-74f5-aa47-9b0397cdfade" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019f22d0-ec66-796f-bb3c-e05567c402d8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfRevenueAbstract_019f22d0-ec66-78a6-b356-09cdbeccb250" 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_019f22d0-ec66-7ac9-b3c6-5abfbf9abac3" xlink:to="loc_us-gaap_CostOfRevenueAbstract_019f22d0-ec66-78a6-b356-09cdbeccb250" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfRevenue_019f22d0-ec66-7dc3-ba4d-bc56a027c15d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CostOfRevenue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostOfRevenueAbstract_019f22d0-ec66-78a6-b356-09cdbeccb250" xlink:to="loc_us-gaap_CostOfRevenue_019f22d0-ec66-7dc3-ba4d-bc56a027c15d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GrossProfit_019f22d0-ec66-7a4f-b130-92b6931bae24" 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_019f22d0-ec66-7ac9-b3c6-5abfbf9abac3" xlink:to="loc_us-gaap_GrossProfit_019f22d0-ec66-7a4f-b130-92b6931bae24" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpensesAbstract_019f22d0-ec66-77f0-8504-aebf4b69fcdb" 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_019f22d0-ec66-7ac9-b3c6-5abfbf9abac3" xlink:to="loc_us-gaap_OperatingExpensesAbstract_019f22d0-ec66-77f0-8504-aebf4b69fcdb" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpense_019f22d0-ec66-77e9-8666-f2cbec67b3c3" 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_019f22d0-ec66-77f0-8504-aebf4b69fcdb" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpense_019f22d0-ec66-77e9-8666-f2cbec67b3c3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingAndMarketingExpense_019f22d0-ec66-79f9-8268-9e79fcbfd9c2" 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_019f22d0-ec66-77f0-8504-aebf4b69fcdb" xlink:to="loc_us-gaap_SellingAndMarketingExpense_019f22d0-ec66-79f9-8268-9e79fcbfd9c2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpense_019f22d0-ec66-7bba-bbb5-d902dadc5feb" 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_019f22d0-ec66-77f0-8504-aebf4b69fcdb" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpense_019f22d0-ec66-7bba-bbb5-d902dadc5feb" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCharges_019f4ade-898d-75a9-be02-4720bae9cc32" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringCharges"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_019f22d0-ec66-77f0-8504-aebf4b69fcdb" xlink:to="loc_us-gaap_RestructuringCharges_019f4ade-898d-75a9-be02-4720bae9cc32" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpenses_019f22d0-ec66-7168-b412-4a07425ca9d9" 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_019f22d0-ec66-77f0-8504-aebf4b69fcdb" xlink:to="loc_us-gaap_OperatingExpenses_019f22d0-ec66-7168-b412-4a07425ca9d9" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_019f22d0-ec66-78ba-9aa1-3901b518bcc7" 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_019f22d0-ec66-7ac9-b3c6-5abfbf9abac3" xlink:to="loc_us-gaap_OperatingIncomeLoss_019f22d0-ec66-78ba-9aa1-3901b518bcc7" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonoperatingIncomeExpense_019f22d0-ec66-73a5-bfb3-130910cc328f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NonoperatingIncomeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019f22d0-ec66-7ac9-b3c6-5abfbf9abac3" xlink:to="loc_us-gaap_NonoperatingIncomeExpense_019f22d0-ec66-73a5-bfb3-130910cc328f" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019f22d0-ec66-75c4-b8bc-6229b0591190" 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_019f22d0-ec66-7ac9-b3c6-5abfbf9abac3" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019f22d0-ec66-75c4-b8bc-6229b0591190" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_019f22d0-ec66-7f00-ba93-24a547469995" 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_019f22d0-ec66-7ac9-b3c6-5abfbf9abac3" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_019f22d0-ec66-7f00-ba93-24a547469995" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019f22d0-ec66-73c4-ab0d-ade756ab7db2" 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_019f22d0-ec66-7ac9-b3c6-5abfbf9abac3" xlink:to="loc_us-gaap_NetIncomeLoss_019f22d0-ec66-73c4-ab0d-ade756ab7db2" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasic_019f22d0-ec66-71e0-874e-c5e1ddb6a3bd" 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_StatementLineItems_019f22d0-ec66-7ac9-b3c6-5abfbf9abac3" xlink:to="loc_us-gaap_EarningsPerShareBasic_019f22d0-ec66-71e0-874e-c5e1ddb6a3bd" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareDiluted_019f22d0-ec66-770f-a3b4-832b77bebbb5" 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_StatementLineItems_019f22d0-ec66-7ac9-b3c6-5abfbf9abac3" xlink:to="loc_us-gaap_EarningsPerShareDiluted_019f22d0-ec66-770f-a3b4-832b77bebbb5" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_019f22d0-ec66-7c84-b754-23b842cb6dbf" 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_StatementLineItems_019f22d0-ec66-7ac9-b3c6-5abfbf9abac3" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_019f22d0-ec66-7c84-b754-23b842cb6dbf" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_019f4ae6-70ee-742e-b238-ce5334f32b9d" 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_StatementLineItems_019f22d0-ec66-7ac9-b3c6-5abfbf9abac3" xlink:to="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_019f4ae6-70ee-742e-b238-ce5334f32b9d" xlink:type="arc" order="12"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.corp.kaltura.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFSTOCKHOLDERSEQUITY" xlink:type="simple" xlink:href="kltr-20260630.xsd#CONDENSEDCONSOLIDATEDSTATEMENTSOFSTOCKHOLDERSEQUITY"/>
  <link:definitionLink xlink:role="http://www.corp.kaltura.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFSTOCKHOLDERSEQUITY" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_019f5e97-938e-7d7a-8cc2-cdcc61f72a4a" 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_019f5e97-938e-7bb6-98f0-b7d8b403586e" 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_019f5e97-938e-7d7a-8cc2-cdcc61f72a4a" xlink:to="loc_us-gaap_StatementTable_019f5e97-938e-7bb6-98f0-b7d8b403586e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_019f5e97-938e-7434-a425-6eb9b760f565" 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_019f5e97-938e-7bb6-98f0-b7d8b403586e" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_019f5e97-938e-7434-a425-6eb9b760f565" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019f5e97-938e-7434-a425-6eb9b760f565_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_019f5e97-938e-7434-a425-6eb9b760f565" xlink:to="loc_us-gaap_EquityComponentDomain_019f5e97-938e-7434-a425-6eb9b760f565_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019f5e97-938e-7e43-b6d1-9541cac16cab" 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_019f5e97-938e-7434-a425-6eb9b760f565" xlink:to="loc_us-gaap_EquityComponentDomain_019f5e97-938e-7e43-b6d1-9541cac16cab" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_019f5e97-938e-7972-ae17-8738af62af16" 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_019f5e97-938e-7e43-b6d1-9541cac16cab" xlink:to="loc_us-gaap_CommonStockMember_019f5e97-938e-7972-ae17-8738af62af16" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonMember_019f5e97-938e-70da-b0c3-6e259612330c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TreasuryStockCommonMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019f5e97-938e-7e43-b6d1-9541cac16cab" xlink:to="loc_us-gaap_TreasuryStockCommonMember_019f5e97-938e-70da-b0c3-6e259612330c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_019f5e97-938e-7478-868e-5c1dedb24a67" 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_019f5e97-938e-7e43-b6d1-9541cac16cab" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_019f5e97-938e-7478-868e-5c1dedb24a67" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComprehensiveIncomeMember_019f5e97-938e-71d2-8e12-2d887510deb8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019f5e97-938e-7e43-b6d1-9541cac16cab" xlink:to="loc_us-gaap_ComprehensiveIncomeMember_019f5e97-938e-71d2-8e12-2d887510deb8" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_019f5e97-938e-78d6-8cf4-723d9f5dd1b1" 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_019f5e97-938e-7e43-b6d1-9541cac16cab" xlink:to="loc_us-gaap_RetainedEarningsMember_019f5e97-938e-78d6-8cf4-723d9f5dd1b1" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019f5e97-938e-78b9-a5ce-ff0fffcb5ffc" 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_019f5e97-938e-7d7a-8cc2-cdcc61f72a4a" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019f5e97-938e-78b9-a5ce-ff0fffcb5ffc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_019f5e97-938e-74df-84e6-2b73041e6a47" 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_019f5e97-938e-78b9-a5ce-ff0fffcb5ffc" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_019f5e97-938e-74df-84e6-2b73041e6a47" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019f5e97-938e-7342-ac14-70382daf6f92" 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_019f5e97-938e-78b9-a5ce-ff0fffcb5ffc" xlink:to="loc_us-gaap_StockholdersEquity_019f5e97-938e-7342-ac14-70382daf6f92" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonShares_019f5e97-938e-7142-bed1-90e3d98229f7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TreasuryStockCommonShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019f5e97-938e-78b9-a5ce-ff0fffcb5ffc" xlink:to="loc_us-gaap_TreasuryStockCommonShares_019f5e97-938e-7142-bed1-90e3d98229f7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_019f5e97-938e-71ba-9e17-597d99b28cd2" 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_019f5e97-938e-78b9-a5ce-ff0fffcb5ffc" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_019f5e97-938e-71ba-9e17-597d99b28cd2" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_AdjustmentsToAdditionalPaidInCapitalSettlementOfEquityClassifiedShareBasedPaymentAwards_019f5e97-938e-75df-b6c1-0fab805762b7" xlink:href="kltr-20260630.xsd#kltr_AdjustmentsToAdditionalPaidInCapitalSettlementOfEquityClassifiedShareBasedPaymentAwards"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019f5e97-938e-78b9-a5ce-ff0fffcb5ffc" xlink:to="loc_kltr_AdjustmentsToAdditionalPaidInCapitalSettlementOfEquityClassifiedShareBasedPaymentAwards_019f5e97-938e-75df-b6c1-0fab805762b7" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockSharesAcquired_019f5e97-938e-7676-9702-5b4432851250" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TreasuryStockSharesAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019f5e97-938e-78b9-a5ce-ff0fffcb5ffc" xlink:to="loc_us-gaap_TreasuryStockSharesAcquired_019f5e97-938e-7676-9702-5b4432851250" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_019f5e97-938e-7e28-8c92-b2300b5f32ac" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TreasuryStockValueAcquiredCostMethod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019f5e97-938e-78b9-a5ce-ff0fffcb5ffc" xlink:to="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_019f5e97-938e-7e28-8c92-b2300b5f32ac" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_019f5e97-938e-75d0-b2f6-94a1e63ee27f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019f5e97-938e-78b9-a5ce-ff0fffcb5ffc" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_019f5e97-938e-75d0-b2f6-94a1e63ee27f" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_019f5e97-938e-75ff-b74e-5a636ec9a94e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019f5e97-938e-78b9-a5ce-ff0fffcb5ffc" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_019f5e97-938e-75ff-b74e-5a636ec9a94e" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_019f5e97-938e-74b8-8310-d2833870cb02" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019f5e97-938e-78b9-a5ce-ff0fffcb5ffc" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_019f5e97-938e-74b8-8310-d2833870cb02" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019f5e97-938e-7dc6-8421-c60a0a74a44b" 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_019f5e97-938e-78b9-a5ce-ff0fffcb5ffc" xlink:to="loc_us-gaap_NetIncomeLoss_019f5e97-938e-7dc6-8421-c60a0a74a44b" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_019f5e97-938e-7a9f-bb61-ff458abd3310" 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_019f5e97-938e-73f6-96b7-99ecfb35120b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonShares_019f5e97-938e-7ef9-a22c-3c4b2ed545a5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TreasuryStockCommonShares"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.corp.kaltura.com/role/BASISOFPRESENTATIONANDSUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESDetails" xlink:type="simple" xlink:href="kltr-20260630.xsd#BASISOFPRESENTATIONANDSUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESDetails"/>
  <link:definitionLink xlink:role="http://www.corp.kaltura.com/role/BASISOFPRESENTATIONANDSUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EntityWideRevenueMajorCustomerLineItems_019f6ea4-b529-7ce8-8442-3d79364fbae7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EntityWideRevenueMajorCustomerLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTable_019f6ea4-b529-717b-a58f-0e6a1419559a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConcentrationRiskTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EntityWideRevenueMajorCustomerLineItems_019f6ea4-b529-7ce8-8442-3d79364fbae7" xlink:to="loc_us-gaap_ConcentrationRiskTable_019f6ea4-b529-717b-a58f-0e6a1419559a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MajorCustomersAxis_019f6ea4-b529-7b3d-a1c3-63d73aee6866" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MajorCustomersAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable_019f6ea4-b529-717b-a58f-0e6a1419559a" xlink:to="loc_srt_MajorCustomersAxis_019f6ea4-b529-7b3d-a1c3-63d73aee6866" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_019f6ea4-b529-7b3d-a1c3-63d73aee6866_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_MajorCustomersAxis_019f6ea4-b529-7b3d-a1c3-63d73aee6866" xlink:to="loc_srt_NameOfMajorCustomerDomain_019f6ea4-b529-7b3d-a1c3-63d73aee6866_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_019f6ea4-b529-7ba2-b90c-cd40df327d22" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_MajorCustomersAxis_019f6ea4-b529-7b3d-a1c3-63d73aee6866" xlink:to="loc_srt_NameOfMajorCustomerDomain_019f6ea4-b529-7ba2-b90c-cd40df327d22" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_CustomerAMember_019f6ea4-b529-743f-a181-3451f36d2cf0" xlink:href="kltr-20260630.xsd#kltr_CustomerAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_019f6ea4-b529-7ba2-b90c-cd40df327d22" xlink:to="loc_kltr_CustomerAMember_019f6ea4-b529-743f-a181-3451f36d2cf0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019f6ea4-b529-7f98-88b2-2f5444586314" 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_ConcentrationRiskTable_019f6ea4-b529-717b-a58f-0e6a1419559a" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019f6ea4-b529-7f98-88b2-2f5444586314" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019f6ea4-b529-7f98-88b2-2f5444586314_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_019f6ea4-b529-7f98-88b2-2f5444586314" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019f6ea4-b529-7f98-88b2-2f5444586314_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019f6ea4-b529-7195-8d74-63244c069827" 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_019f6ea4-b529-7f98-88b2-2f5444586314" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019f6ea4-b529-7195-8d74-63244c069827" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerMember_019f6ea4-b529-79e4-a87c-ad7a8e72ce6a" 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_019f6ea4-b529-7195-8d74-63244c069827" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerMember_019f6ea4-b529-79e4-a87c-ad7a8e72ce6a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_019f6ea4-b529-7b57-971f-6d3bcaaeac1a" 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_ConcentrationRiskTable_019f6ea4-b529-717b-a58f-0e6a1419559a" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_019f6ea4-b529-7b57-971f-6d3bcaaeac1a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_019f6ea4-b529-7b57-971f-6d3bcaaeac1a_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_019f6ea4-b529-7b57-971f-6d3bcaaeac1a" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_019f6ea4-b529-7b57-971f-6d3bcaaeac1a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_019f6ea4-b529-7695-975c-c4770057664f" 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_019f6ea4-b529-7b57-971f-6d3bcaaeac1a" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_019f6ea4-b529-7695-975c-c4770057664f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerConcentrationRiskMember_019f6ea4-b529-7340-b46a-5e6f7d4b0649" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CustomerConcentrationRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_019f6ea4-b529-7695-975c-c4770057664f" xlink:to="loc_us-gaap_CustomerConcentrationRiskMember_019f6ea4-b529-7340-b46a-5e6f7d4b0649" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1_019f6ea4-b529-7237-b47f-5cc2df781909" 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_EntityWideRevenueMajorCustomerLineItems_019f6ea4-b529-7ce8-8442-3d79364fbae7" xlink:to="loc_us-gaap_ConcentrationRiskPercentage1_019f6ea4-b529-7237-b47f-5cc2df781909" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.corp.kaltura.com/role/BUSINESSCOMBINATIONSNarrativeDetails" xlink:type="simple" xlink:href="kltr-20260630.xsd#BUSINESSCOMBINATIONSNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.corp.kaltura.com/role/BUSINESSCOMBINATIONSNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_019f4b2e-229a-7e36-80c5-65f603f5fa72" 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_019f4b2d-63c1-7865-9308-1993bf0d7baf" 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_019f4b2e-229a-7e36-80c5-65f603f5fa72" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019f4b2d-63c1-7865-9308-1993bf0d7baf" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_019f4b2d-c62d-74ae-8072-5d4997c62c64" 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_019f4b2d-63c1-7865-9308-1993bf0d7baf" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_019f4b2d-c62d-74ae-8072-5d4997c62c64" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f4b2d-c62d-74ae-8072-5d4997c62c64_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_019f4b2d-c62d-74ae-8072-5d4997c62c64" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f4b2d-c62d-74ae-8072-5d4997c62c64_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f4b2e-6b4f-74fd-92d6-6385d2699905" 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_019f4b2d-c62d-74ae-8072-5d4997c62c64" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f4b2e-6b4f-74fd-92d6-6385d2699905" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_PathFactoryHoldingsULCMember_019f4b2e-6b4f-776e-9ca4-3b3d924a485b" xlink:href="kltr-20260630.xsd#kltr_PathFactoryHoldingsULCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f4b2e-6b4f-74fd-92d6-6385d2699905" xlink:to="loc_kltr_PathFactoryHoldingsULCMember_019f4b2e-6b4f-776e-9ca4-3b3d924a485b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_BlueRushDigitalMediaCorpMember_019fb8b6-d309-761a-99ac-55a608a3f382" xlink:href="kltr-20260630.xsd#kltr_BlueRushDigitalMediaCorpMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f4b2e-6b4f-74fd-92d6-6385d2699905" xlink:to="loc_kltr_BlueRushDigitalMediaCorpMember_019fb8b6-d309-761a-99ac-55a608a3f382" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019f6ed4-8f2f-78bd-a086-12068181c95a" 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_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019f4b2d-63c1-7865-9308-1993bf0d7baf" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019f6ed4-8f2f-78bd-a086-12068181c95a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f6ed4-8f2f-78bd-a086-12068181c95a_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_019f6ed4-8f2f-78bd-a086-12068181c95a" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f6ed4-8f2f-78bd-a086-12068181c95a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f6ed4-8f2f-708b-a516-821c6449a923" 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_019f6ed4-8f2f-78bd-a086-12068181c95a" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f6ed4-8f2f-708b-a516-821c6449a923" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TechnologyBasedIntangibleAssetsMember_019f6ed4-8f2f-7924-8174-f520b0cbe01e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TechnologyBasedIntangibleAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f6ed4-8f2f-708b-a516-821c6449a923" xlink:to="loc_us-gaap_TechnologyBasedIntangibleAssetsMember_019f6ed4-8f2f-7924-8174-f520b0cbe01e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelationshipsMember_019f6ed4-8f2f-7fc8-b021-70f6b89ae293" 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_019f6ed4-8f2f-708b-a516-821c6449a923" xlink:to="loc_us-gaap_CustomerRelationshipsMember_019f6ed4-8f2f-7fc8-b021-70f6b89ae293" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_DevelopedTechnologyCustomerRelationshipsMember_019fa911-0363-71a8-9347-db0f1724ab07" xlink:href="kltr-20260630.xsd#kltr_DevelopedTechnologyCustomerRelationshipsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f6ed4-8f2f-708b-a516-821c6449a923" xlink:to="loc_kltr_DevelopedTechnologyCustomerRelationshipsMember_019fa911-0363-71a8-9347-db0f1724ab07" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_019f4b2e-6b4f-7994-ab0b-d1c736f7eec1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f4b2e-229a-7e36-80c5-65f603f5fa72" xlink:to="loc_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_019f4b2e-6b4f-7994-ab0b-d1c736f7eec1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesGross_019f8efe-bd16-72b9-8e12-b34678e1dc92" 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_019f4b2e-229a-7e36-80c5-65f603f5fa72" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesGross_019f8efe-bd16-72b9-8e12-b34678e1dc92" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinitelivedIntangibleAssetsAcquired1_019f8efc-3818-7bc6-ab0c-85231ed3fd07" 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_BusinessAcquisitionLineItems_019f4b2e-229a-7e36-80c5-65f603f5fa72" xlink:to="loc_us-gaap_FinitelivedIntangibleAssetsAcquired1_019f8efc-3818-7bc6-ab0c-85231ed3fd07" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_019fb2a6-b798-7d7d-800a-d894251d1298" 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_BusinessAcquisitionLineItems_019f4b2e-229a-7e36-80c5-65f603f5fa72" xlink:to="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_019fb2a6-b798-7d7d-800a-d894251d1298" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductibleAmount_019f4b2e-c000-7edb-aee2-4a13025d85df" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductibleAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f4b2e-229a-7e36-80c5-65f603f5fa72" xlink:to="loc_us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductibleAmount_019f4b2e-c000-7edb-aee2-4a13025d85df" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_019f8efd-4c4f-7c77-bb7e-adc97c5d9b00" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationAcquisitionRelatedCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f4b2e-229a-7e36-80c5-65f603f5fa72" xlink:to="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_019f8efd-4c4f-7c77-bb7e-adc97c5d9b00" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionsProFormaRevenue_019fb2ab-b9cf-7ec0-bfab-b7afa450fcb3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionsProFormaRevenue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f4b2e-229a-7e36-80c5-65f603f5fa72" xlink:to="loc_us-gaap_BusinessAcquisitionsProFormaRevenue_019fb2ab-b9cf-7ec0-bfab-b7afa450fcb3" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss_019fb2ab-b9cf-7512-a086-ecb1b5964041" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f4b2e-229a-7e36-80c5-65f603f5fa72" xlink:to="loc_us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss_019fb2ab-b9cf-7512-a086-ecb1b5964041" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_019fb2ab-3a34-76d8-aa30-f3f3cb545aee" 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_BusinessAcquisitionLineItems_019f4b2e-229a-7e36-80c5-65f603f5fa72" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_019fb2ab-3a34-76d8-aa30-f3f3cb545aee" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_019faa48-593a-7084-a3a0-bcb611508aed" 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_019f4b2e-229a-7e36-80c5-65f603f5fa72" xlink:to="loc_us-gaap_Goodwill_019faa48-593a-7084-a3a0-bcb611508aed" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue_019fb2ab-3a34-764f-921d-b7c447b57f99" 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_BusinessAcquisitionLineItems_019f4b2e-229a-7e36-80c5-65f603f5fa72" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue_019fb2ab-3a34-764f-921d-b7c447b57f99" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayable_019fb2ab-3a34-7897-b2be-33b0b1016cab" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f4b2e-229a-7e36-80c5-65f603f5fa72" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayable_019fb2ab-3a34-7897-b2be-33b0b1016cab" xlink:type="arc" order="11"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.corp.kaltura.com/role/BUSINESSCOMBINATIONSScheduleofPreliminaryPurchasePriceAllocationoftheFairValuesoftheAssetsAcquiredandLiabilitiesAssumedDetails" xlink:type="simple" xlink:href="kltr-20260630.xsd#BUSINESSCOMBINATIONSScheduleofPreliminaryPurchasePriceAllocationoftheFairValuesoftheAssetsAcquiredandLiabilitiesAssumedDetails"/>
  <link:definitionLink xlink:role="http://www.corp.kaltura.com/role/BUSINESSCOMBINATIONSScheduleofPreliminaryPurchasePriceAllocationoftheFairValuesoftheAssetsAcquiredandLiabilitiesAssumedDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_019f4b17-deee-7df7-9bc2-45689f2fc895" 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_019f4b15-3ec8-78d3-bdf5-4a652dc5dd7c" 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_019f4b17-deee-7df7-9bc2-45689f2fc895" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019f4b15-3ec8-78d3-bdf5-4a652dc5dd7c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_019f4b15-a889-7645-8b54-ab30771c8b37" 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_019f4b15-3ec8-78d3-bdf5-4a652dc5dd7c" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_019f4b15-a889-7645-8b54-ab30771c8b37" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f4b15-a889-7645-8b54-ab30771c8b37_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_019f4b15-a889-7645-8b54-ab30771c8b37" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f4b15-a889-7645-8b54-ab30771c8b37_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f4b16-1841-7bf1-baad-71f2a5639dd8" 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_019f4b15-a889-7645-8b54-ab30771c8b37" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f4b16-1841-7bf1-baad-71f2a5639dd8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_PathFactoryHoldingsULCMember_019f4b16-8f4b-788a-a9f7-e09c96cada88" xlink:href="kltr-20260630.xsd#kltr_PathFactoryHoldingsULCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f4b16-1841-7bf1-baad-71f2a5639dd8" xlink:to="loc_kltr_PathFactoryHoldingsULCMember_019f4b16-8f4b-788a-a9f7-e09c96cada88" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents_019f4b18-2c10-79f4-9613-ecf1bb1690fb" 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_BusinessAcquisitionLineItems_019f4b17-deee-7df7-9bc2-45689f2fc895" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents_019f4b18-2c10-79f4-9613-ecf1bb1690fb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_019f4b1b-021f-7112-bce0-29466d91fb18" 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_BusinessAcquisitionLineItems_019f4b17-deee-7df7-9bc2-45689f2fc895" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_019f4b1b-021f-7112-bce0-29466d91fb18" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther_019f4b1b-578f-7e11-9db9-0d5fc227e1ca" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f4b17-deee-7df7-9bc2-45689f2fc895" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther_019f4b1b-578f-7e11-9db9-0d5fc227e1ca" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_019f4b1b-a441-7c0c-b4ea-a6caae24407f" 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_BusinessAcquisitionLineItems_019f4b17-deee-7df7-9bc2-45689f2fc895" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_019f4b1b-a441-7c0c-b4ea-a6caae24407f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_019f4b1b-e375-7983-83a9-9853278a8436" 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_BusinessAcquisitionLineItems_019f4b17-deee-7df7-9bc2-45689f2fc895" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_019f4b1b-e375-7983-83a9-9853278a8436" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_019f4b1c-2f94-7efd-a118-5248992bf518" 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_019f4b17-deee-7df7-9bc2-45689f2fc895" xlink:to="loc_us-gaap_Goodwill_019f4b1c-2f94-7efd-a118-5248992bf518" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_BusinessCombinationRecognizedAssetsAcquiredAssetsIncludingGoodwill_019f4b1d-8f91-7e4a-854f-8aea31100242" xlink:href="kltr-20260630.xsd#kltr_BusinessCombinationRecognizedAssetsAcquiredAssetsIncludingGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f4b17-deee-7df7-9bc2-45689f2fc895" xlink:to="loc_kltr_BusinessCombinationRecognizedAssetsAcquiredAssetsIncludingGoodwill_019f4b1d-8f91-7e4a-854f-8aea31100242" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_BusinessCombinationRecognizedLiabilityAssumedAccruedExpensesAndOtherCurrentLiabilities_019f4b1e-4110-7ba8-8946-56cf9c3b2c62" xlink:href="kltr-20260630.xsd#kltr_BusinessCombinationRecognizedLiabilityAssumedAccruedExpensesAndOtherCurrentLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f4b17-deee-7df7-9bc2-45689f2fc895" xlink:to="loc_kltr_BusinessCombinationRecognizedLiabilityAssumedAccruedExpensesAndOtherCurrentLiabilities_019f4b1e-4110-7ba8-8946-56cf9c3b2c62" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayable_019f4b1e-8d1b-795f-a0e9-661b475288b8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f4b17-deee-7df7-9bc2-45689f2fc895" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayable_019f4b1e-8d1b-795f-a0e9-661b475288b8" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue_019f4b1e-d115-7bed-8df5-b294f56997c8" 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_BusinessAcquisitionLineItems_019f4b17-deee-7df7-9bc2-45689f2fc895" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue_019f4b1e-d115-7bed-8df5-b294f56997c8" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_019f4b1f-2341-7ca7-8388-38372d47b8bf" 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_BusinessAcquisitionLineItems_019f4b17-deee-7df7-9bc2-45689f2fc895" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_019f4b1f-2341-7ca7-8388-38372d47b8bf" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferred1_019f4b21-e8fb-7e4c-b7f8-26aa8355392e" 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_019f4b17-deee-7df7-9bc2-45689f2fc895" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferred1_019f4b21-e8fb-7e4c-b7f8-26aa8355392e" xlink:type="arc" order="11"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.corp.kaltura.com/role/BUSINESSCOMBINATIONSProFormaInformationDetails" xlink:type="simple" xlink:href="kltr-20260630.xsd#BUSINESSCOMBINATIONSProFormaInformationDetails"/>
  <link:definitionLink xlink:role="http://www.corp.kaltura.com/role/BUSINESSCOMBINATIONSProFormaInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionProFormaInformationNonrecurringAdjustmentLineItems_019fb2a9-485d-73b4-bd61-d26345591748" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionProFormaInformationNonrecurringAdjustmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionProFormaInformationNonrecurringAdjustmentsTable_019fb2a9-485d-7435-835f-e8cc357053b8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionProFormaInformationNonrecurringAdjustmentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionProFormaInformationNonrecurringAdjustmentLineItems_019fb2a9-485d-73b4-bd61-d26345591748" xlink:to="loc_us-gaap_BusinessAcquisitionProFormaInformationNonrecurringAdjustmentsTable_019fb2a9-485d-7435-835f-e8cc357053b8" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_019fb2a9-485d-7703-8e05-b51b8f5719f2" 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_BusinessAcquisitionProFormaInformationNonrecurringAdjustmentsTable_019fb2a9-485d-7435-835f-e8cc357053b8" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_019fb2a9-485d-7703-8e05-b51b8f5719f2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019fb2a9-485d-7703-8e05-b51b8f5719f2_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_019fb2a9-485d-7703-8e05-b51b8f5719f2" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019fb2a9-485d-7703-8e05-b51b8f5719f2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019fb2a9-485d-7bc1-87a0-da74f0ce0635" 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_019fb2a9-485d-7703-8e05-b51b8f5719f2" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019fb2a9-485d-7bc1-87a0-da74f0ce0635" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_PathFactoryHoldingsULCMember_019fb2a9-485d-71ff-a5bc-4cb0b7c744ed" xlink:href="kltr-20260630.xsd#kltr_PathFactoryHoldingsULCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019fb2a9-485d-7bc1-87a0-da74f0ce0635" xlink:to="loc_kltr_PathFactoryHoldingsULCMember_019fb2a9-485d-71ff-a5bc-4cb0b7c744ed" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionsProFormaRevenue_019fb2a9-485d-7d75-aacf-aa46be247495" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionsProFormaRevenue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionProFormaInformationNonrecurringAdjustmentLineItems_019fb2a9-485d-73b4-bd61-d26345591748" xlink:to="loc_us-gaap_BusinessAcquisitionsProFormaRevenue_019fb2a9-485d-7d75-aacf-aa46be247495" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss_019fb2a9-485d-7f65-a637-34e08ff63dc4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionProFormaInformationNonrecurringAdjustmentLineItems_019fb2a9-485d-73b4-bd61-d26345591748" xlink:to="loc_us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss_019fb2a9-485d-7f65-a637-34e08ff63dc4" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.corp.kaltura.com/role/REVENUESFROMCONTRACTSWITHCUSTOMERSScheduleofDisaggregationofRevenueDetails" xlink:type="simple" xlink:href="kltr-20260630.xsd#REVENUESFROMCONTRACTSWITHCUSTOMERSScheduleofDisaggregationofRevenueDetails"/>
  <link:definitionLink xlink:role="http://www.corp.kaltura.com/role/REVENUESFROMCONTRACTSWITHCUSTOMERSScheduleofDisaggregationofRevenueDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_019f6ee6-26ef-732e-b8be-565084fbf610" 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_019f6ee6-26ee-7d2f-a92b-0787a252d194" 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_019f6ee6-26ef-732e-b8be-565084fbf610" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_019f6ee6-26ee-7d2f-a92b-0787a252d194" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019f6ee6-26ef-7b06-9a10-7dbf9745312a" 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_DisaggregationOfRevenueTable_019f6ee6-26ee-7d2f-a92b-0787a252d194" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019f6ee6-26ef-7b06-9a10-7dbf9745312a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019f6ee6-26ef-7b06-9a10-7dbf9745312a_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_019f6ee6-26ef-7b06-9a10-7dbf9745312a" xlink:to="loc_us-gaap_SegmentDomain_019f6ee6-26ef-7b06-9a10-7dbf9745312a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019f6ee6-26ef-709f-97d8-f66b4cc69069" 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_019f6ee6-26ef-7b06-9a10-7dbf9745312a" xlink:to="loc_us-gaap_SegmentDomain_019f6ee6-26ef-709f-97d8-f66b4cc69069" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_EnterpriseEducationAndTechnologySegmentMember_019f6ee6-26ef-7cdc-bb98-244bd9663380" xlink:href="kltr-20260630.xsd#kltr_EnterpriseEducationAndTechnologySegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f6ee6-26ef-709f-97d8-f66b4cc69069" xlink:to="loc_kltr_EnterpriseEducationAndTechnologySegmentMember_019f6ee6-26ef-7cdc-bb98-244bd9663380" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_MediaAndTelecomSegmentMember_019f6ee6-26ef-7818-8936-e85a52154dcd" xlink:href="kltr-20260630.xsd#kltr_MediaAndTelecomSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f6ee6-26ef-709f-97d8-f66b4cc69069" xlink:to="loc_kltr_MediaAndTelecomSegmentMember_019f6ee6-26ef-7818-8936-e85a52154dcd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_019f6ee6-26ef-7c65-9209-156b32c1f9e7" 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_DisaggregationOfRevenueTable_019f6ee6-26ee-7d2f-a92b-0787a252d194" xlink:to="loc_srt_ProductOrServiceAxis_019f6ee6-26ef-7c65-9209-156b32c1f9e7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019f6ee6-26ef-7c65-9209-156b32c1f9e7_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_019f6ee6-26ef-7c65-9209-156b32c1f9e7" xlink:to="loc_srt_ProductsAndServicesDomain_019f6ee6-26ef-7c65-9209-156b32c1f9e7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019f6ee6-26ef-7a23-99f4-4437ca12fe9c" 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_019f6ee6-26ef-7c65-9209-156b32c1f9e7" xlink:to="loc_srt_ProductsAndServicesDomain_019f6ee6-26ef-7a23-99f4-4437ca12fe9c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_SubscriptionMember_019f6ee6-26ef-761e-9c1c-5f55266f0b74" xlink:href="kltr-20260630.xsd#kltr_SubscriptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f6ee6-26ef-7a23-99f4-4437ca12fe9c" xlink:to="loc_kltr_SubscriptionMember_019f6ee6-26ef-761e-9c1c-5f55266f0b74" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_ProfessionalServicesMember_019f6ee6-26ef-712f-825e-0ce97fb6584b" xlink:href="kltr-20260630.xsd#kltr_ProfessionalServicesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f6ee6-26ef-7a23-99f4-4437ca12fe9c" xlink:to="loc_kltr_ProfessionalServicesMember_019f6ee6-26ef-712f-825e-0ce97fb6584b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019f6ee6-26ef-7946-890e-67456ec42ea6" 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_019f6ee6-26ef-732e-b8be-565084fbf610" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019f6ee6-26ef-7946-890e-67456ec42ea6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_RevenueFromContractWithCustomerExcludingAssessedTaxPercent_019f6ee6-26ef-7eef-b18e-762cf8da144a" xlink:href="kltr-20260630.xsd#kltr_RevenueFromContractWithCustomerExcludingAssessedTaxPercent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019f6ee6-26ef-732e-b8be-565084fbf610" xlink:to="loc_kltr_RevenueFromContractWithCustomerExcludingAssessedTaxPercent_019f6ee6-26ef-7eef-b18e-762cf8da144a" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.corp.kaltura.com/role/REVENUESFROMCONTRACTSWITHCUSTOMERSScheduleOfDisaggregatedRevenueByRegionDetails" xlink:type="simple" xlink:href="kltr-20260630.xsd#REVENUESFROMCONTRACTSWITHCUSTOMERSScheduleOfDisaggregatedRevenueByRegionDetails"/>
  <link:definitionLink xlink:role="http://www.corp.kaltura.com/role/REVENUESFROMCONTRACTSWITHCUSTOMERSScheduleOfDisaggregatedRevenueByRegionDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_019f6ee6-26ef-7430-8bf6-e6f5aee48cd3" 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_019f6ee6-26ef-7648-9791-d334b1fc9582" 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_019f6ee6-26ef-7430-8bf6-e6f5aee48cd3" xlink:to="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_019f6ee6-26ef-7648-9791-d334b1fc9582" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_019f6ee6-26ef-70f8-8ea0-781a4fe12d7f" 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_019f6ee6-26ef-7648-9791-d334b1fc9582" xlink:to="loc_srt_StatementGeographicalAxis_019f6ee6-26ef-70f8-8ea0-781a4fe12d7f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_019f6ee6-26ef-70f8-8ea0-781a4fe12d7f_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_019f6ee6-26ef-70f8-8ea0-781a4fe12d7f" xlink:to="loc_srt_SegmentGeographicalDomain_019f6ee6-26ef-70f8-8ea0-781a4fe12d7f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_019f6ee6-26ef-7787-9b3a-5d6bf9c3699d" 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_019f6ee6-26ef-70f8-8ea0-781a4fe12d7f" xlink:to="loc_srt_SegmentGeographicalDomain_019f6ee6-26ef-7787-9b3a-5d6bf9c3699d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_019f6ee6-26ef-7223-9ea7-677b2a9fa4d8" 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_019f6ee6-26ef-7787-9b3a-5d6bf9c3699d" xlink:to="loc_country_US_019f6ee6-26ef-7223-9ea7-677b2a9fa4d8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EMEAMember_019f6ee6-26ef-7039-acc8-a124c54f2f4c" 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_019f6ee6-26ef-7787-9b3a-5d6bf9c3699d" xlink:to="loc_us-gaap_EMEAMember_019f6ee6-26ef-7039-acc8-a124c54f2f4c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_OtherCountriesMember_019f6ee6-26ef-735f-86eb-5dffcd461212" xlink:href="kltr-20260630.xsd#kltr_OtherCountriesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019f6ee6-26ef-7787-9b3a-5d6bf9c3699d" xlink:to="loc_kltr_OtherCountriesMember_019f6ee6-26ef-735f-86eb-5dffcd461212" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_019f6ee6-26ef-7395-9573-2cfbc2a4df11" 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_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_019f6ee6-26ef-7648-9791-d334b1fc9582" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_019f6ee6-26ef-7395-9573-2cfbc2a4df11" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_019f6ee6-26ef-7395-9573-2cfbc2a4df11_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_019f6ee6-26ef-7395-9573-2cfbc2a4df11" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_019f6ee6-26ef-7395-9573-2cfbc2a4df11_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_019f6ee6-26ef-74dd-bc1c-0cb02c9cd198" 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_019f6ee6-26ef-7395-9573-2cfbc2a4df11" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_019f6ee6-26ef-74dd-bc1c-0cb02c9cd198" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromRightsConcentrationRiskMember_019f6ee6-26ef-795e-bf53-693020d7f4e5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueFromRightsConcentrationRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_019f6ee6-26ef-74dd-bc1c-0cb02c9cd198" xlink:to="loc_us-gaap_RevenueFromRightsConcentrationRiskMember_019f6ee6-26ef-795e-bf53-693020d7f4e5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019f6ee6-26ef-7f63-a3ee-a9c3d2e3ff24" 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_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_019f6ee6-26ef-7648-9791-d334b1fc9582" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019f6ee6-26ef-7f63-a3ee-a9c3d2e3ff24" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019f6ee6-26ef-7f63-a3ee-a9c3d2e3ff24_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_019f6ee6-26ef-7f63-a3ee-a9c3d2e3ff24" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019f6ee6-26ef-7f63-a3ee-a9c3d2e3ff24_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019f6ee6-26ef-7caf-bcd5-c06105c71900" 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_019f6ee6-26ef-7f63-a3ee-a9c3d2e3ff24" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019f6ee6-26ef-7caf-bcd5-c06105c71900" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerMember_019f8f01-8ea6-7eea-8647-afa371d20b17" 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_019f6ee6-26ef-7caf-bcd5-c06105c71900" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerMember_019f8f01-8ea6-7eea-8647-afa371d20b17" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019f6ee6-26ef-7abe-b7ec-a238e143da3f" 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_019f6ee6-26ef-7430-8bf6-e6f5aee48cd3" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019f6ee6-26ef-7abe-b7ec-a238e143da3f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_RevenueFromContractWithCustomerExcludingAssessedTaxPercent_019f6ee6-26ef-70d9-b4aa-d8a1779b51ca" xlink:href="kltr-20260630.xsd#kltr_RevenueFromContractWithCustomerExcludingAssessedTaxPercent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_019f6ee6-26ef-7430-8bf6-e6f5aee48cd3" xlink:to="loc_kltr_RevenueFromContractWithCustomerExcludingAssessedTaxPercent_019f6ee6-26ef-70d9-b4aa-d8a1779b51ca" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.corp.kaltura.com/role/REVENUESFROMCONTRACTSWITHCUSTOMERSNarrativeDetails" xlink:type="simple" xlink:href="kltr-20260630.xsd#REVENUESFROMCONTRACTSWITHCUSTOMERSNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.corp.kaltura.com/role/REVENUESFROMCONTRACTSWITHCUSTOMERSNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_019f6ee6-26ef-71d1-aeb9-8c6909329ea7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_019f6ee6-26ef-7794-8c2c-f07c18efcdb3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_019f6ee6-26ef-71d1-aeb9-8c6909329ea7" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_019f6ee6-26ef-7794-8c2c-f07c18efcdb3" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsNotesLoansAndFinancingReceivablesByBillingStatusTypeAxis_019f6ee6-26ef-7b30-8c40-713a4aa0f3bb" 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_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_019f6ee6-26ef-7794-8c2c-f07c18efcdb3" xlink:to="loc_us-gaap_AccountsNotesLoansAndFinancingReceivablesByBillingStatusTypeAxis_019f6ee6-26ef-7b30-8c40-713a4aa0f3bb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReceivablesBillingStatusDomain_019f6ee6-26ef-7b30-8c40-713a4aa0f3bb_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_019f6ee6-26ef-7b30-8c40-713a4aa0f3bb" xlink:to="loc_us-gaap_ReceivablesBillingStatusDomain_019f6ee6-26ef-7b30-8c40-713a4aa0f3bb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReceivablesBillingStatusDomain_019f6ee6-26ef-7236-885d-46777507f7d9" 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_019f6ee6-26ef-7b30-8c40-713a4aa0f3bb" xlink:to="loc_us-gaap_ReceivablesBillingStatusDomain_019f6ee6-26ef-7236-885d-46777507f7d9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BilledRevenuesMember_019f6ee6-26ef-7d83-a91f-de7b65d07273" 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_019f6ee6-26ef-7236-885d-46777507f7d9" xlink:to="loc_us-gaap_BilledRevenuesMember_019f6ee6-26ef-7d83-a91f-de7b65d07273" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnbilledRevenuesMember_019f6ee6-26ef-7cf8-8409-ed07fb832d3b" 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_019f6ee6-26ef-7236-885d-46777507f7d9" xlink:to="loc_us-gaap_UnbilledRevenuesMember_019f6ee6-26ef-7cf8-8409-ed07fb832d3b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_019f6ee6-26ef-7d6c-a920-0457dbbd6c90" 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_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_019f6ee6-26ef-7794-8c2c-f07c18efcdb3" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_019f6ee6-26ef-7d6c-a920-0457dbbd6c90" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligation_019f6ee6-26ef-799d-8507-02d94289bd0a" 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_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_019f6ee6-26ef-71d1-aeb9-8c6909329ea7" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligation_019f6ee6-26ef-799d-8507-02d94289bd0a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_019f6ee6-26ef-7810-b09d-21a189fb66c6" 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_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_019f6ee6-26ef-71d1-aeb9-8c6909329ea7" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_019f6ee6-26ef-7810-b09d-21a189fb66c6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_019f6ee6-26ef-7498-a859-6bee323b2d00" 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_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_019f6ee6-26ef-71d1-aeb9-8c6909329ea7" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_019f6ee6-26ef-7498-a859-6bee323b2d00" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.corp.kaltura.com/role/REVENUESFROMCONTRACTSWITHCUSTOMERSNarrativeDetails_1" xlink:type="simple" xlink:href="kltr-20260630.xsd#REVENUESFROMCONTRACTSWITHCUSTOMERSNarrativeDetails_1"/>
  <link:definitionLink xlink:role="http://www.corp.kaltura.com/role/REVENUESFROMCONTRACTSWITHCUSTOMERSNarrativeDetails_1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_019f6ee6-26ef-71d1-aeb9-8c6909329ea7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_019f6ee6-26ef-7794-8c2c-f07c18efcdb3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_019f6ee6-26ef-71d1-aeb9-8c6909329ea7" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_019f6ee6-26ef-7794-8c2c-f07c18efcdb3" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsNotesLoansAndFinancingReceivablesByBillingStatusTypeAxis_019f6ee6-26ef-7b30-8c40-713a4aa0f3bb" 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_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_019f6ee6-26ef-7794-8c2c-f07c18efcdb3" xlink:to="loc_us-gaap_AccountsNotesLoansAndFinancingReceivablesByBillingStatusTypeAxis_019f6ee6-26ef-7b30-8c40-713a4aa0f3bb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReceivablesBillingStatusDomain_019f6ee6-26ef-7b30-8c40-713a4aa0f3bb_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_019f6ee6-26ef-7b30-8c40-713a4aa0f3bb" xlink:to="loc_us-gaap_ReceivablesBillingStatusDomain_019f6ee6-26ef-7b30-8c40-713a4aa0f3bb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReceivablesBillingStatusDomain_019f6ee6-26ef-7236-885d-46777507f7d9" 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_019f6ee6-26ef-7b30-8c40-713a4aa0f3bb" xlink:to="loc_us-gaap_ReceivablesBillingStatusDomain_019f6ee6-26ef-7236-885d-46777507f7d9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BilledRevenuesMember_019f6ee6-26ef-7d83-a91f-de7b65d07273" 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_019f6ee6-26ef-7236-885d-46777507f7d9" xlink:to="loc_us-gaap_BilledRevenuesMember_019f6ee6-26ef-7d83-a91f-de7b65d07273" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnbilledRevenuesMember_019f6ee6-26ef-7cf8-8409-ed07fb832d3b" 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_019f6ee6-26ef-7236-885d-46777507f7d9" xlink:to="loc_us-gaap_UnbilledRevenuesMember_019f6ee6-26ef-7cf8-8409-ed07fb832d3b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligation_019f6ee6-26ef-799d-8507-02d94289bd0a" 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_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_019f6ee6-26ef-71d1-aeb9-8c6909329ea7" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligation_019f6ee6-26ef-799d-8507-02d94289bd0a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_019f6ee6-26ef-7810-b09d-21a189fb66c6" 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_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_019f6ee6-26ef-71d1-aeb9-8c6909329ea7" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_019f6ee6-26ef-7810-b09d-21a189fb66c6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_019f6ee6-26ef-7498-a859-6bee323b2d00" 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_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_019f6ee6-26ef-71d1-aeb9-8c6909329ea7" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_019f6ee6-26ef-7498-a859-6bee323b2d00" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.corp.kaltura.com/role/REVENUESFROMCONTRACTSWITHCUSTOMERSScheduleofContractwithCustomerContractAssetContractLiabilityandReceivableDetails" xlink:type="simple" xlink:href="kltr-20260630.xsd#REVENUESFROMCONTRACTSWITHCUSTOMERSScheduleofContractwithCustomerContractAssetContractLiabilityandReceivableDetails"/>
  <link:definitionLink xlink:role="http://www.corp.kaltura.com/role/REVENUESFROMCONTRACTSWITHCUSTOMERSScheduleofContractwithCustomerContractAssetContractLiabilityandReceivableDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizedContractCostLineItems_019f6ee6-26ef-7a56-80ce-4303dcb45447" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CapitalizedContractCostLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizedContractCostTable_019f6ee6-26ef-7499-b032-00be9fb6b313" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CapitalizedContractCostTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_CapitalizedContractCostLineItems_019f6ee6-26ef-7a56-80ce-4303dcb45447" xlink:to="loc_us-gaap_CapitalizedContractCostTable_019f6ee6-26ef-7499-b032-00be9fb6b313" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizedContractCostAxis_019f6ee6-26ef-753a-a266-265d8c93e020" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CapitalizedContractCostAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_CapitalizedContractCostTable_019f6ee6-26ef-7499-b032-00be9fb6b313" xlink:to="loc_us-gaap_CapitalizedContractCostAxis_019f6ee6-26ef-753a-a266-265d8c93e020" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizedContractCostDomain_019f6ee6-26ef-753a-a266-265d8c93e020_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CapitalizedContractCostDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CapitalizedContractCostAxis_019f6ee6-26ef-753a-a266-265d8c93e020" xlink:to="loc_us-gaap_CapitalizedContractCostDomain_019f6ee6-26ef-753a-a266-265d8c93e020_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizedContractCostDomain_019f6ee6-26ef-721e-a200-554f18372cc7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CapitalizedContractCostDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CapitalizedContractCostAxis_019f6ee6-26ef-753a-a266-265d8c93e020" xlink:to="loc_us-gaap_CapitalizedContractCostDomain_019f6ee6-26ef-721e-a200-554f18372cc7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_CostsToObtainContractMember_019f6ee6-26ef-79ac-ae9f-f4114d6f01b2" xlink:href="kltr-20260630.xsd#kltr_CostsToObtainContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CapitalizedContractCostDomain_019f6ee6-26ef-721e-a200-554f18372cc7" xlink:to="loc_kltr_CostsToObtainContractMember_019f6ee6-26ef-79ac-ae9f-f4114d6f01b2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_CostsToFulfillContractMember_019f6ee6-26ef-7aaf-a5cc-cc2e952eb893" xlink:href="kltr-20260630.xsd#kltr_CostsToFulfillContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CapitalizedContractCostDomain_019f6ee6-26ef-721e-a200-554f18372cc7" xlink:to="loc_kltr_CostsToFulfillContractMember_019f6ee6-26ef-7aaf-a5cc-cc2e952eb893" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_CapitalizedContractCostRollForward_019f6ee6-26ef-7698-9c05-c1d56096df46" xlink:href="kltr-20260630.xsd#kltr_CapitalizedContractCostRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CapitalizedContractCostLineItems_019f6ee6-26ef-7a56-80ce-4303dcb45447" xlink:to="loc_kltr_CapitalizedContractCostRollForward_019f6ee6-26ef-7698-9c05-c1d56096df46" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizedContractCostNet_019f6ee6-26ef-77f3-ab6f-b216d022e096" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CapitalizedContractCostNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_kltr_CapitalizedContractCostRollForward_019f6ee6-26ef-7698-9c05-c1d56096df46" xlink:to="loc_us-gaap_CapitalizedContractCostNet_019f6ee6-26ef-77f3-ab6f-b216d022e096" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_AdditionsToDeferredContractCostsDuringPeriod_019f6ee6-26ef-78ed-8ae5-276891f6b912" xlink:href="kltr-20260630.xsd#kltr_AdditionsToDeferredContractCostsDuringPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_kltr_CapitalizedContractCostRollForward_019f6ee6-26ef-7698-9c05-c1d56096df46" xlink:to="loc_kltr_AdditionsToDeferredContractCostsDuringPeriod_019f6ee6-26ef-78ed-8ae5-276891f6b912" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizedContractCostAmortization_019f6ee6-26ef-7d93-96cc-6d8dc20b1768" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CapitalizedContractCostAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_kltr_CapitalizedContractCostRollForward_019f6ee6-26ef-7698-9c05-c1d56096df46" xlink:to="loc_us-gaap_CapitalizedContractCostAmortization_019f6ee6-26ef-7d93-96cc-6d8dc20b1768" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizedContractCostNet_019f6ee6-26ef-7a65-b834-e3ca2950080e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CapitalizedContractCostNet"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizedContractCostNetCurrent_019f6ee6-26ef-7cec-b99e-877d611713ca" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CapitalizedContractCostNetCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CapitalizedContractCostLineItems_019f6ee6-26ef-7a56-80ce-4303dcb45447" xlink:to="loc_us-gaap_CapitalizedContractCostNetCurrent_019f6ee6-26ef-7cec-b99e-877d611713ca" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizedContractCostNetNoncurrent_019f6ee6-26ef-7173-912d-bc69fad7d7be" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CapitalizedContractCostNetNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CapitalizedContractCostLineItems_019f6ee6-26ef-7a56-80ce-4303dcb45447" xlink:to="loc_us-gaap_CapitalizedContractCostNetNoncurrent_019f6ee6-26ef-7173-912d-bc69fad7d7be" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizedContractCostNet_019f6ee6-26ef-7759-80be-567edb12f975" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CapitalizedContractCostNet"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.corp.kaltura.com/role/MARKETABLESECURITIESScheduleofAvailableforSaleSecuritiesReconciliationDetails" xlink:type="simple" xlink:href="kltr-20260630.xsd#MARKETABLESECURITIESScheduleofAvailableforSaleSecuritiesReconciliationDetails"/>
  <link:definitionLink xlink:role="http://www.corp.kaltura.com/role/MARKETABLESECURITIESScheduleofAvailableforSaleSecuritiesReconciliationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_019f6efd-9782-7790-ad14-9c0a8e61d545" 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_019f6efd-9782-7c09-873b-1a38f78f1ef7" 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_019f6efd-9782-7790-ad14-9c0a8e61d545" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_019f6efd-9782-7c09-873b-1a38f78f1ef7" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_019f6efd-9782-7913-99ee-5b232b4283d3" 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_019f6efd-9782-7c09-873b-1a38f78f1ef7" xlink:to="loc_us-gaap_FinancialInstrumentAxis_019f6efd-9782-7913-99ee-5b232b4283d3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019f6efd-9782-7913-99ee-5b232b4283d3_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_019f6efd-9782-7913-99ee-5b232b4283d3" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019f6efd-9782-7913-99ee-5b232b4283d3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019f6efd-9782-77d8-8c34-bc67afb676cb" 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_019f6efd-9782-7913-99ee-5b232b4283d3" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019f6efd-9782-77d8-8c34-bc67afb676cb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateBondSecuritiesMember_019f6efd-9782-72b5-aac0-37c09b707434" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CorporateBondSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019f6efd-9782-77d8-8c34-bc67afb676cb" xlink:to="loc_us-gaap_CorporateBondSecuritiesMember_019f6efd-9782-72b5-aac0-37c09b707434" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MunicipalBondsMember_019f6efd-9782-72d9-8dcf-62c70d3ac7b9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MunicipalBondsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019f6efd-9782-77d8-8c34-bc67afb676cb" xlink:to="loc_us-gaap_MunicipalBondsMember_019f6efd-9782-72d9-8dcf-62c70d3ac7b9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AgencySecuritiesMember_019f6efd-9782-7cc3-b1bc-a92d31e06167" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AgencySecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019f6efd-9782-77d8-8c34-bc67afb676cb" xlink:to="loc_us-gaap_AgencySecuritiesMember_019f6efd-9782-7cc3-b1bc-a92d31e06167" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USTreasurySecuritiesMember_019f6efd-9782-7ba6-9572-f7b7336d9612" 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_019f6efd-9782-77d8-8c34-bc67afb676cb" xlink:to="loc_us-gaap_USTreasurySecuritiesMember_019f6efd-9782-7ba6-9572-f7b7336d9612" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialPaperMember_019f6efd-9782-7ad9-9d1f-6fc3786345c6" 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_019f6efd-9782-77d8-8c34-bc67afb676cb" xlink:to="loc_us-gaap_CommercialPaperMember_019f6efd-9782-7ad9-9d1f-6fc3786345c6" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAbstract_019f6efd-9782-74ea-9fda-f9b059931325" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_019f6efd-9782-7790-ad14-9c0a8e61d545" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAbstract_019f6efd-9782-74ea-9fda-f9b059931325" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost_019f6efd-9782-760f-bc1e-ccb17f256641" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAbstract_019f6efd-9782-74ea-9fda-f9b059931325" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost_019f6efd-9782-760f-bc1e-ccb17f256641" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_AvailableForSaleMaturitiesWithinOneYearGrossUnrealizedGains_019f6efd-9782-73b4-891f-5d1c8c9f5d60" xlink:href="kltr-20260630.xsd#kltr_AvailableForSaleMaturitiesWithinOneYearGrossUnrealizedGains"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAbstract_019f6efd-9782-74ea-9fda-f9b059931325" xlink:to="loc_kltr_AvailableForSaleMaturitiesWithinOneYearGrossUnrealizedGains_019f6efd-9782-73b4-891f-5d1c8c9f5d60" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_AvailableForSaleMaturesWithinOneYearGrossUnrealizedLosses_019f6efd-9782-7bf2-bad1-b4032ea5c95c" xlink:href="kltr-20260630.xsd#kltr_AvailableForSaleMaturesWithinOneYearGrossUnrealizedLosses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAbstract_019f6efd-9782-74ea-9fda-f9b059931325" xlink:to="loc_kltr_AvailableForSaleMaturesWithinOneYearGrossUnrealizedLosses_019f6efd-9782-7bf2-bad1-b4032ea5c95c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue_019f6efd-9782-7e5b-8943-7abd3cdf39bf" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAbstract_019f6efd-9782-74ea-9fda-f9b059931325" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue_019f6efd-9782-7e5b-8943-7abd3cdf39bf" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost_019f6efd-9782-7221-b269-7bde816fe9f9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_019f6efd-9782-7790-ad14-9c0a8e61d545" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost_019f6efd-9782-7221-b269-7bde816fe9f9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_AvailableForSaleMaturesAfterOneYearGrossUnrealizedGains_019f6efd-9782-7feb-a363-abbb2646bee9" xlink:href="kltr-20260630.xsd#kltr_AvailableForSaleMaturesAfterOneYearGrossUnrealizedGains"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_019f6efd-9782-7790-ad14-9c0a8e61d545" xlink:to="loc_kltr_AvailableForSaleMaturesAfterOneYearGrossUnrealizedGains_019f6efd-9782-7feb-a363-abbb2646bee9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_AvailableForSaleMaturesAfterOneYearGrossUnrealizedLosses_019f6efd-9782-7652-afe8-0807376a728a" xlink:href="kltr-20260630.xsd#kltr_AvailableForSaleMaturesAfterOneYearGrossUnrealizedLosses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_019f6efd-9782-7790-ad14-9c0a8e61d545" xlink:to="loc_kltr_AvailableForSaleMaturesAfterOneYearGrossUnrealizedLosses_019f6efd-9782-7652-afe8-0807376a728a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue_019f6efd-9782-7c96-b8e4-284d4420a1e3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_019f6efd-9782-7790-ad14-9c0a8e61d545" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue_019f6efd-9782-7c96-b8e4-284d4420a1e3" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_019f6efd-9782-72ee-9f7f-54e1a3c4d827" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_019f6efd-9782-7790-ad14-9c0a8e61d545" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_019f6efd-9782-72ee-9f7f-54e1a3c4d827" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_019f6efd-9782-7ab3-9b29-36cb4f3c1d50" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_019f6efd-9782-7790-ad14-9c0a8e61d545" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_019f6efd-9782-7ab3-9b29-36cb4f3c1d50" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_019f6efd-9782-78a6-875b-612c673daebc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_019f6efd-9782-7790-ad14-9c0a8e61d545" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_019f6efd-9782-78a6-875b-612c673daebc" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_019f6efd-9782-75a0-a948-37e1bb471640" 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_019f6efd-9782-7790-ad14-9c0a8e61d545" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_019f6efd-9782-75a0-a948-37e1bb471640" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.corp.kaltura.com/role/FAIRVALUEMEASUREMENTSScheduleofFairValueAssetsandLiabilitiesMeasuredonRecurringBasisDetails" xlink:type="simple" xlink:href="kltr-20260630.xsd#FAIRVALUEMEASUREMENTSScheduleofFairValueAssetsandLiabilitiesMeasuredonRecurringBasisDetails"/>
  <link:definitionLink xlink:role="http://www.corp.kaltura.com/role/FAIRVALUEMEASUREMENTSScheduleofFairValueAssetsandLiabilitiesMeasuredonRecurringBasisDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019f6f08-4e8e-760e-b1a4-1b2616f6d02a" 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_019f6f08-4e8e-790d-8c54-660e06cfa336" 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_019f6f08-4e8e-760e-b1a4-1b2616f6d02a" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019f6f08-4e8e-790d-8c54-660e06cfa336" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAxis_019f6f08-4e8e-79ab-bc9d-4d94b968c8e8" 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_019f6f08-4e8e-790d-8c54-660e06cfa336" xlink:to="loc_us-gaap_CashAndCashEquivalentsAxis_019f6f08-4e8e-79ab-bc9d-4d94b968c8e8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_019f6f08-4e8e-79ab-bc9d-4d94b968c8e8_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_019f6f08-4e8e-79ab-bc9d-4d94b968c8e8" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_019f6f08-4e8e-79ab-bc9d-4d94b968c8e8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_019f6f08-4e8e-7942-9b1f-868eb9b7dde1" 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_019f6f08-4e8e-79ab-bc9d-4d94b968c8e8" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_019f6f08-4e8e-7942-9b1f-868eb9b7dde1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MoneyMarketFundsMember_019f6f08-4e8e-711b-97f3-dd8e31e703f4" 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_019f6f08-4e8e-7942-9b1f-868eb9b7dde1" xlink:to="loc_us-gaap_MoneyMarketFundsMember_019f6f08-4e8e-711b-97f3-dd8e31e703f4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019f6f08-4e8e-76bf-bde1-8b6b5f37131c" 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_019f6f08-4e8e-790d-8c54-660e06cfa336" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019f6f08-4e8e-76bf-bde1-8b6b5f37131c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019f6f08-4e8e-76bf-bde1-8b6b5f37131c_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_019f6f08-4e8e-76bf-bde1-8b6b5f37131c" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019f6f08-4e8e-76bf-bde1-8b6b5f37131c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019f6f08-4e8e-7e28-adb5-b1abc7a51388" 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_019f6f08-4e8e-76bf-bde1-8b6b5f37131c" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019f6f08-4e8e-7e28-adb5-b1abc7a51388" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_019f6f08-4e8e-7f66-a116-8d6661d01de0" 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_019f6f08-4e8e-7e28-adb5-b1abc7a51388" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_019f6f08-4e8e-7f66-a116-8d6661d01de0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_019f6f08-4e8e-72d6-a98f-a079564dfbe8" 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_019f6f08-4e8e-7e28-adb5-b1abc7a51388" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_019f6f08-4e8e-72d6-a98f-a079564dfbe8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_019f6f08-4e8e-7ee4-bfbc-c9dcf616dc58" 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_019f6f08-4e8e-7e28-adb5-b1abc7a51388" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_019f6f08-4e8e-7ee4-bfbc-c9dcf616dc58" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_019f6f08-4e8e-79b3-b034-e601c1127031" 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_019f6f08-4e8e-790d-8c54-660e06cfa336" xlink:to="loc_us-gaap_FinancialInstrumentAxis_019f6f08-4e8e-79b3-b034-e601c1127031" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019f6f08-4e8e-79b3-b034-e601c1127031_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_019f6f08-4e8e-79b3-b034-e601c1127031" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019f6f08-4e8e-79b3-b034-e601c1127031_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019f6f08-4e8e-79a6-a4ca-432af90a229a" 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_019f6f08-4e8e-79b3-b034-e601c1127031" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019f6f08-4e8e-79a6-a4ca-432af90a229a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateBondSecuritiesMember_019f6f08-4e8e-757d-bd93-6ce6ff4c6030" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CorporateBondSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019f6f08-4e8e-79a6-a4ca-432af90a229a" xlink:to="loc_us-gaap_CorporateBondSecuritiesMember_019f6f08-4e8e-757d-bd93-6ce6ff4c6030" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USTreasurySecuritiesMember_019f6f08-4e8e-7953-8020-702ea2b5dea4" 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_019f6f08-4e8e-79a6-a4ca-432af90a229a" xlink:to="loc_us-gaap_USTreasurySecuritiesMember_019f6f08-4e8e-7953-8020-702ea2b5dea4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialPaperMember_019f6f08-4e8e-7d7a-9e43-bee3b8084321" 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_019f6f08-4e8e-79a6-a4ca-432af90a229a" xlink:to="loc_us-gaap_CommercialPaperMember_019f6f08-4e8e-7d7a-9e43-bee3b8084321" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AgencySecuritiesMember_019f6f08-4e8e-775b-a873-8250ca4740d8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AgencySecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019f6f08-4e8e-79a6-a4ca-432af90a229a" xlink:to="loc_us-gaap_AgencySecuritiesMember_019f6f08-4e8e-775b-a873-8250ca4740d8" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MunicipalBondsMember_019f6f08-4e8e-7007-9935-026ebc969ace" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MunicipalBondsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019f6f08-4e8e-79a6-a4ca-432af90a229a" xlink:to="loc_us-gaap_MunicipalBondsMember_019f6f08-4e8e-7007-9935-026ebc969ace" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsFairValueDisclosureAbstract_019f6f08-4e8e-7793-abfe-529fe4aa9230" 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_019f6f08-4e8e-760e-b1a4-1b2616f6d02a" xlink:to="loc_us-gaap_AssetsFairValueDisclosureAbstract_019f6f08-4e8e-7793-abfe-529fe4aa9230" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_019f6f08-4e8e-77ea-bfed-fd43ec0d02ab" 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_019f6f08-4e8e-7793-abfe-529fe4aa9230" xlink:to="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_019f6f08-4e8e-77ea-bfed-fd43ec0d02ab" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecuritiesCurrent_019f6f08-4e8e-7878-8b62-8ad16621acd4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecuritiesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_019f6f08-4e8e-7793-abfe-529fe4aa9230" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecuritiesCurrent_019f6f08-4e8e-7878-8b62-8ad16621acd4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecuritiesNoncurrent_019f6f08-4e8e-7fd2-8d3c-f7cceb90855f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecuritiesNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_019f6f08-4e8e-7793-abfe-529fe4aa9230" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecuritiesNoncurrent_019f6f08-4e8e-7fd2-8d3c-f7cceb90855f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_RestrictedBankDepositCurrentFairValueDisclosure_019f6f08-4e8e-7b5e-af0a-f46092f880de" xlink:href="kltr-20260630.xsd#kltr_RestrictedBankDepositCurrentFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_019f6f08-4e8e-7793-abfe-529fe4aa9230" xlink:to="loc_kltr_RestrictedBankDepositCurrentFairValueDisclosure_019f6f08-4e8e-7b5e-af0a-f46092f880de" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssetsCurrent_019f6f08-4e8e-7959-af25-77deb32df617" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeAssetsCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_019f6f08-4e8e-7793-abfe-529fe4aa9230" xlink:to="loc_us-gaap_DerivativeAssetsCurrent_019f6f08-4e8e-7959-af25-77deb32df617" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_RestrictedBankDepositNoncurrentFairValueDisclosure_019f6f08-4e8e-7c71-97a7-e31f84b261aa" xlink:href="kltr-20260630.xsd#kltr_RestrictedBankDepositNoncurrentFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_019f6f08-4e8e-7793-abfe-529fe4aa9230" xlink:to="loc_kltr_RestrictedBankDepositNoncurrentFairValueDisclosure_019f6f08-4e8e-7c71-97a7-e31f84b261aa" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesFairValueDisclosureAbstract_019f6f08-4e8e-7e81-989f-d172b58320dc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesFairValueDisclosureAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019f6f08-4e8e-760e-b1a4-1b2616f6d02a" xlink:to="loc_us-gaap_LiabilitiesFairValueDisclosureAbstract_019f6f08-4e8e-7e81-989f-d172b58320dc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilitiesCurrent_019f6f0a-95e3-7e39-bd22-1441ed6ccf07" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeLiabilitiesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesFairValueDisclosureAbstract_019f6f08-4e8e-7e81-989f-d172b58320dc" xlink:to="loc_us-gaap_DerivativeLiabilitiesCurrent_019f6f0a-95e3-7e39-bd22-1441ed6ccf07" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_019f6f08-4e8e-7c26-9c66-8d464e7ce3b4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationContingentConsiderationLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesFairValueDisclosureAbstract_019f6f08-4e8e-7e81-989f-d172b58320dc" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_019f6f08-4e8e-7c26-9c66-8d464e7ce3b4" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.corp.kaltura.com/role/FAIRVALUEMEASUREMENTSNarrativeDetails" xlink:type="simple" xlink:href="kltr-20260630.xsd#FAIRVALUEMEASUREMENTSNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.corp.kaltura.com/role/FAIRVALUEMEASUREMENTSNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019f6f08-4e8e-7164-9393-f93992fd0533" 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_019f6f08-4e8e-7188-a75c-15552d725947" 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_019f6f08-4e8e-7164-9393-f93992fd0533" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019f6f08-4e8e-7188-a75c-15552d725947" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_019f6f08-4e8e-7f7e-a22e-bea472dda598" 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_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019f6f08-4e8e-7188-a75c-15552d725947" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_019f6f08-4e8e-7f7e-a22e-bea472dda598" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f6f08-4e8e-7f7e-a22e-bea472dda598_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_019f6f08-4e8e-7f7e-a22e-bea472dda598" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f6f08-4e8e-7f7e-a22e-bea472dda598_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f6f08-4e8e-712e-9b87-a27c9b2d2473" 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_019f6f08-4e8e-7f7e-a22e-bea472dda598" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f6f08-4e8e-712e-9b87-a27c9b2d2473" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_ESelf.AILtd.Member_019f6f08-4e8e-7b9c-9bf8-e69f9f5cb91a" xlink:href="kltr-20260630.xsd#kltr_ESelf.AILtd.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f6f08-4e8e-712e-9b87-a27c9b2d2473" xlink:to="loc_kltr_ESelf.AILtd.Member_019f6f08-4e8e-7b9c-9bf8-e69f9f5cb91a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_BusinessCombinationContingentConsiderationMaximumTargetAchievablePercent_019f6f08-4e8e-7139-9584-522b6be83ce0" xlink:href="kltr-20260630.xsd#kltr_BusinessCombinationContingentConsiderationMaximumTargetAchievablePercent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019f6f08-4e8e-7164-9393-f93992fd0533" xlink:to="loc_kltr_BusinessCombinationContingentConsiderationMaximumTargetAchievablePercent_019f6f08-4e8e-7139-9584-522b6be83ce0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueHigh_019f6f08-4e8e-7d68-9ec3-33ef692fa43a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueHigh"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019f6f08-4e8e-7164-9393-f93992fd0533" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueHigh_019f6f08-4e8e-7d68-9ec3-33ef692fa43a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_019f6f08-4e8e-7019-95f2-a8c868a0f3b5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationContingentConsiderationLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019f6f08-4e8e-7164-9393-f93992fd0533" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_019f6f08-4e8e-7019-95f2-a8c868a0f3b5" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.corp.kaltura.com/role/FAIRVALUEMEASUREMENTSScheduleofChangesintheEarnoutConsiderationDetails" xlink:type="simple" xlink:href="kltr-20260630.xsd#FAIRVALUEMEASUREMENTSScheduleofChangesintheEarnoutConsiderationDetails"/>
  <link:definitionLink xlink:role="http://www.corp.kaltura.com/role/FAIRVALUEMEASUREMENTSScheduleofChangesintheEarnoutConsiderationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_019f6f08-4e8e-77c8-b9fe-9cb3b0f97581" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable_019f6f08-4e8e-7d31-ac74-ce82573ec4a1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_019f6f08-4e8e-77c8-b9fe-9cb3b0f97581" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable_019f6f08-4e8e-7d31-ac74-ce82573ec4a1" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByLiabilityClassAxis_019f6f08-4e8e-7cec-908a-f7ec36cdadb5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByLiabilityClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable_019f6f08-4e8e-7d31-ac74-ce82573ec4a1" xlink:to="loc_us-gaap_FairValueByLiabilityClassAxis_019f6f08-4e8e-7cec-908a-f7ec36cdadb5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_019f6f08-4e8e-7cec-908a-f7ec36cdadb5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByLiabilityClassAxis_019f6f08-4e8e-7cec-908a-f7ec36cdadb5" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_019f6f08-4e8e-7cec-908a-f7ec36cdadb5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_019f6f08-4e8e-7d0d-ba8f-10b255514fac" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByLiabilityClassAxis_019f6f08-4e8e-7cec-908a-f7ec36cdadb5" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_019f6f08-4e8e-7d0d-ba8f-10b255514fac" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_EarnOutConsiderationMember_019f6f08-4e8e-7c89-ba7c-56593cc44768" xlink:href="kltr-20260630.xsd#kltr_EarnOutConsiderationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_019f6f08-4e8e-7d0d-ba8f-10b255514fac" xlink:to="loc_kltr_EarnOutConsiderationMember_019f6f08-4e8e-7c89-ba7c-56593cc44768" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_019f6f08-4e8e-7bb4-a369-57dce3550da2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_019f6f08-4e8e-77c8-b9fe-9cb3b0f97581" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_019f6f08-4e8e-7bb4-a369-57dce3550da2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue_019f6f08-4e8e-73c9-a5b1-13aac9f3af3e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_019f6f08-4e8e-7bb4-a369-57dce3550da2" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue_019f6f08-4e8e-73c9-a5b1-13aac9f3af3e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings_019f6f08-4e8e-7266-98aa-ba0c4a356af2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_019f6f08-4e8e-7bb4-a369-57dce3550da2" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings_019f6f08-4e8e-7266-98aa-ba0c4a356af2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue_019f6f08-4e8e-7eb2-90d7-5f9788a922ee" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.corp.kaltura.com/role/DERIVATIVESANDHEDGINGScheduleofCashFlowHedgingInstrumentsStatementsofFinancialPerformanceandFinancialPositionLocationDetails" xlink:type="simple" xlink:href="kltr-20260630.xsd#DERIVATIVESANDHEDGINGScheduleofCashFlowHedgingInstrumentsStatementsofFinancialPerformanceandFinancialPositionLocationDetails"/>
  <link:definitionLink xlink:role="http://www.corp.kaltura.com/role/DERIVATIVESANDHEDGINGScheduleofCashFlowHedgingInstrumentsStatementsofFinancialPerformanceandFinancialPositionLocationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems_019f22d0-ec66-7588-a029-6153f31bdadf" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_019f22d0-ec66-7e42-bbac-36af58c68ee6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems_019f22d0-ec66-7588-a029-6153f31bdadf" xlink:to="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_019f22d0-ec66-7e42-bbac-36af58c68ee6" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementOfIncomeLocationBalanceAxis_019f22d0-ec66-7450-ad2d-f4d17741d646" 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_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_019f22d0-ec66-7e42-bbac-36af58c68ee6" xlink:to="loc_us-gaap_StatementOfIncomeLocationBalanceAxis_019f22d0-ec66-7450-ad2d-f4d17741d646" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationAxis_019f5963-18bc-7f40-971d-9ec1efe41bf2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_019f22d0-ec66-7e42-bbac-36af58c68ee6" xlink:to="loc_us-gaap_HedgingDesignationAxis_019f5963-18bc-7f40-971d-9ec1efe41bf2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_019f5963-18bc-7f40-971d-9ec1efe41bf2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_019f5963-18bc-7f40-971d-9ec1efe41bf2" xlink:to="loc_us-gaap_HedgingDesignationDomain_019f5963-18bc-7f40-971d-9ec1efe41bf2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_019f5963-18bc-7d6f-86e2-45f93ebcf220" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_019f5963-18bc-7f40-971d-9ec1efe41bf2" xlink:to="loc_us-gaap_HedgingDesignationDomain_019f5963-18bc-7d6f-86e2-45f93ebcf220" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DesignatedAsHedgingInstrumentMember_019f5963-60e6-71f5-aaf0-155d704d434f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DesignatedAsHedgingInstrumentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_019f5963-18bc-7d6f-86e2-45f93ebcf220" xlink:to="loc_us-gaap_DesignatedAsHedgingInstrumentMember_019f5963-60e6-71f5-aaf0-155d704d434f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeGainLossOnDerivativeNet_019f22d0-ec66-70c0-8dd0-b6de456919bb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeGainLossOnDerivativeNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems_019f22d0-ec66-7588-a029-6153f31bdadf" xlink:to="loc_us-gaap_DerivativeGainLossOnDerivativeNet_019f22d0-ec66-70c0-8dd0-b6de456919bb" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.corp.kaltura.com/role/DERIVATIVESANDHEDGINGScheduleofCashFlowHedgingInstrumentsStatementsofFinancialPerformanceandFinancialPositionLocationDetails_1" xlink:type="simple" xlink:href="kltr-20260630.xsd#DERIVATIVESANDHEDGINGScheduleofCashFlowHedgingInstrumentsStatementsofFinancialPerformanceandFinancialPositionLocationDetails_1"/>
  <link:definitionLink xlink:role="http://www.corp.kaltura.com/role/DERIVATIVESANDHEDGINGScheduleofCashFlowHedgingInstrumentsStatementsofFinancialPerformanceandFinancialPositionLocationDetails_1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems_019f22d0-ec66-7588-a029-6153f31bdadf" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_019f22d0-ec66-7e42-bbac-36af58c68ee6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems_019f22d0-ec66-7588-a029-6153f31bdadf" xlink:to="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_019f22d0-ec66-7e42-bbac-36af58c68ee6" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationAxis_019f5963-18bc-7f40-971d-9ec1efe41bf2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_019f22d0-ec66-7e42-bbac-36af58c68ee6" xlink:to="loc_us-gaap_HedgingDesignationAxis_019f5963-18bc-7f40-971d-9ec1efe41bf2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_019f5963-18bc-7f40-971d-9ec1efe41bf2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_019f5963-18bc-7f40-971d-9ec1efe41bf2" xlink:to="loc_us-gaap_HedgingDesignationDomain_019f5963-18bc-7f40-971d-9ec1efe41bf2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_019f5963-18bc-7d6f-86e2-45f93ebcf220" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_019f5963-18bc-7f40-971d-9ec1efe41bf2" xlink:to="loc_us-gaap_HedgingDesignationDomain_019f5963-18bc-7d6f-86e2-45f93ebcf220" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DesignatedAsHedgingInstrumentMember_019f5963-60e6-71f5-aaf0-155d704d434f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DesignatedAsHedgingInstrumentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_019f5963-18bc-7d6f-86e2-45f93ebcf220" xlink:to="loc_us-gaap_DesignatedAsHedgingInstrumentMember_019f5963-60e6-71f5-aaf0-155d704d434f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeGainLossOnDerivativeNet_019f22d0-ec66-70c0-8dd0-b6de456919bb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeGainLossOnDerivativeNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems_019f22d0-ec66-7588-a029-6153f31bdadf" xlink:to="loc_us-gaap_DerivativeGainLossOnDerivativeNet_019f22d0-ec66-70c0-8dd0-b6de456919bb" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.corp.kaltura.com/role/CONDENSEDCONSOLIDATEDBALANCESHEETCOMPONENTSScheduleofPropertyPlantandEquipmentDetails" xlink:type="simple" xlink:href="kltr-20260630.xsd#CONDENSEDCONSOLIDATEDBALANCESHEETCOMPONENTSScheduleofPropertyPlantandEquipmentDetails"/>
  <link:definitionLink xlink:role="http://www.corp.kaltura.com/role/CONDENSEDCONSOLIDATEDBALANCESHEETCOMPONENTSScheduleofPropertyPlantandEquipmentDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019f6f9e-46e9-72e8-9fcf-d0e5da860876" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_019f6f9e-46e9-7c50-ab93-39693fd4bfd0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019f6f9e-46e9-72e8-9fcf-d0e5da860876" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_019f6f9e-46e9-7c50-ab93-39693fd4bfd0" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_019f6f9e-46e9-7791-b62b-dd034309de1e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_019f6f9e-46e9-7c50-ab93-39693fd4bfd0" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_019f6f9e-46e9-7791-b62b-dd034309de1e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019f6f9e-46e9-7791-b62b-dd034309de1e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_019f6f9e-46e9-7791-b62b-dd034309de1e" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019f6f9e-46e9-7791-b62b-dd034309de1e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019f6f9e-46e9-74da-b749-6d792d60be07" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_019f6f9e-46e9-7791-b62b-dd034309de1e" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019f6f9e-46e9-74da-b749-6d792d60be07" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComputerEquipmentMember_019f6f9e-46e9-7aff-8755-f6259cb098e5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ComputerEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019f6f9e-46e9-74da-b749-6d792d60be07" xlink:to="loc_us-gaap_ComputerEquipmentMember_019f6f9e-46e9-7aff-8755-f6259cb098e5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OfficeEquipmentMember_019f6f9e-46e9-7654-8244-d81ade9f0af3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OfficeEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019f6f9e-46e9-74da-b749-6d792d60be07" xlink:to="loc_us-gaap_OfficeEquipmentMember_019f6f9e-46e9-7654-8244-d81ade9f0af3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LeaseholdImprovementsMember_019f6f9e-46e9-74e0-85a8-64bb8c21d4d2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LeaseholdImprovementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019f6f9e-46e9-74da-b749-6d792d60be07" xlink:to="loc_us-gaap_LeaseholdImprovementsMember_019f6f9e-46e9-74e0-85a8-64bb8c21d4d2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SoftwareDevelopmentMember_019f6f9e-46e9-7286-8066-a0566d2ba6ff" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SoftwareDevelopmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019f6f9e-46e9-74da-b749-6d792d60be07" xlink:to="loc_us-gaap_SoftwareDevelopmentMember_019f6f9e-46e9-7286-8066-a0566d2ba6ff" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentGross_019f6f9e-46e9-7e17-b553-8e80c0376ca5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019f6f9e-46e9-72e8-9fcf-d0e5da860876" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentGross_019f6f9e-46e9-7e17-b553-8e80c0376ca5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_019f6f9e-46e9-7dfa-ac11-abdf94dda69c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019f6f9e-46e9-72e8-9fcf-d0e5da860876" xlink:to="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_019f6f9e-46e9-7dfa-ac11-abdf94dda69c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_019f6f9e-46e9-73c1-9dec-b23880959030" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019f6f9e-46e9-72e8-9fcf-d0e5da860876" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_019f6f9e-46e9-73c1-9dec-b23880959030" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.corp.kaltura.com/role/GOODWILLANDINTANGIBLEASSETSScheduleofFiniteLivedIntangibleAssetsDetails" xlink:type="simple" xlink:href="kltr-20260630.xsd#GOODWILLANDINTANGIBLEASSETSScheduleofFiniteLivedIntangibleAssetsDetails"/>
  <link:definitionLink xlink:role="http://www.corp.kaltura.com/role/GOODWILLANDINTANGIBLEASSETSScheduleofFiniteLivedIntangibleAssetsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems_019f6fa2-a3bd-7a84-9ded-bb68d07fc55b" 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_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable_019f6fa2-a3bd-7403-9bb3-24249928c697" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems_019f6fa2-a3bd-7a84-9ded-bb68d07fc55b" xlink:to="loc_us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable_019f6fa2-a3bd-7403-9bb3-24249928c697" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019f6fa2-a3bd-7b2c-a03c-8d88eaef8d0f" 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_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable_019f6fa2-a3bd-7403-9bb3-24249928c697" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019f6fa2-a3bd-7b2c-a03c-8d88eaef8d0f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f6fa2-a3bd-7b2c-a03c-8d88eaef8d0f_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_019f6fa2-a3bd-7b2c-a03c-8d88eaef8d0f" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f6fa2-a3bd-7b2c-a03c-8d88eaef8d0f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f6fa2-a3bd-75d0-8a25-c62292014b3c" 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_019f6fa2-a3bd-7b2c-a03c-8d88eaef8d0f" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f6fa2-a3bd-75d0-8a25-c62292014b3c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TechnologyBasedIntangibleAssetsMember_019f6fa2-a3bd-7916-a84a-0e2008c5e2c4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TechnologyBasedIntangibleAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f6fa2-a3bd-75d0-8a25-c62292014b3c" xlink:to="loc_us-gaap_TechnologyBasedIntangibleAssetsMember_019f6fa2-a3bd-7916-a84a-0e2008c5e2c4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelationshipsMember_019f6fa2-a3bd-73e0-a80c-533e17f5fc64" 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_019f6fa2-a3bd-75d0-8a25-c62292014b3c" xlink:to="loc_us-gaap_CustomerRelationshipsMember_019f6fa2-a3bd-73e0-a80c-533e17f5fc64" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_019f6fa2-a3bd-7ce5-8416-9c803dea1e9d" 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_019f6fa2-a3bd-7a84-9ded-bb68d07fc55b" xlink:to="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_019f6fa2-a3bd-7ce5-8416-9c803dea1e9d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_019f6fa2-a3bd-79e9-9f29-244e5000493e" 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_AcquiredFiniteLivedIntangibleAssetsLineItems_019f6fa2-a3bd-7a84-9ded-bb68d07fc55b" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_019f6fa2-a3bd-79e9-9f29-244e5000493e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_019f6fa2-a3bd-7a4d-9069-d3702256ecc9" 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_AcquiredFiniteLivedIntangibleAssetsLineItems_019f6fa2-a3bd-7a84-9ded-bb68d07fc55b" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_019f6fa2-a3bd-7a4d-9069-d3702256ecc9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_019f6fa2-a3bd-7a14-9004-4f800bdb588a" 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_AcquiredFiniteLivedIntangibleAssetsLineItems_019f6fa2-a3bd-7a84-9ded-bb68d07fc55b" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_019f6fa2-a3bd-7a14-9004-4f800bdb588a" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.corp.kaltura.com/role/GOODWILLANDINTANGIBLEASSETSScheduleofChangesintheCarryingAmountofGoodwillDetails" xlink:type="simple" xlink:href="kltr-20260630.xsd#GOODWILLANDINTANGIBLEASSETSScheduleofChangesintheCarryingAmountofGoodwillDetails"/>
  <link:definitionLink xlink:role="http://www.corp.kaltura.com/role/GOODWILLANDINTANGIBLEASSETSScheduleofChangesintheCarryingAmountofGoodwillDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillLineItems_019f8fe2-1fcb-7422-b185-72c7406e8ee4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GoodwillLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfGoodwillTable_019f8fe2-1fcb-73b5-a8a1-b2317886462c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfGoodwillTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_GoodwillLineItems_019f8fe2-1fcb-7422-b185-72c7406e8ee4" xlink:to="loc_us-gaap_ScheduleOfGoodwillTable_019f8fe2-1fcb-73b5-a8a1-b2317886462c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019f8fe2-1fcb-7712-b458-04b9e2fe918b" 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_ScheduleOfGoodwillTable_019f8fe2-1fcb-73b5-a8a1-b2317886462c" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019f8fe2-1fcb-7712-b458-04b9e2fe918b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019f8fe2-1fcb-7712-b458-04b9e2fe918b_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_019f8fe2-1fcb-7712-b458-04b9e2fe918b" xlink:to="loc_us-gaap_SegmentDomain_019f8fe2-1fcb-7712-b458-04b9e2fe918b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019f8fe2-1fcb-7e16-9f51-b1f973cf0be5" 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_019f8fe2-1fcb-7712-b458-04b9e2fe918b" xlink:to="loc_us-gaap_SegmentDomain_019f8fe2-1fcb-7e16-9f51-b1f973cf0be5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_EnterpriseEducationAndTechnologySegmentMember_019f8fe2-1fcb-7c6a-9fd2-bc5219166e72" xlink:href="kltr-20260630.xsd#kltr_EnterpriseEducationAndTechnologySegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f8fe2-1fcb-7e16-9f51-b1f973cf0be5" xlink:to="loc_kltr_EnterpriseEducationAndTechnologySegmentMember_019f8fe2-1fcb-7c6a-9fd2-bc5219166e72" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_MediaAndTelecomSegmentMember_019f8fe2-1fcb-75af-82a9-9c01a49d5929" xlink:href="kltr-20260630.xsd#kltr_MediaAndTelecomSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f8fe2-1fcb-7e16-9f51-b1f973cf0be5" xlink:to="loc_kltr_MediaAndTelecomSegmentMember_019f8fe2-1fcb-75af-82a9-9c01a49d5929" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillRollForward_019f8fe2-1fcb-7bcb-bc00-ad23a356a2c0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GoodwillRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_019f8fe2-1fcb-7422-b185-72c7406e8ee4" xlink:to="loc_us-gaap_GoodwillRollForward_019f8fe2-1fcb-7bcb-bc00-ad23a356a2c0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_019f8fe2-1fcb-74fe-ac37-5ceaab77348f" 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_GoodwillRollForward_019f8fe2-1fcb-7bcb-bc00-ad23a356a2c0" xlink:to="loc_us-gaap_Goodwill_019f8fe2-1fcb-74fe-ac37-5ceaab77348f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillAcquiredDuringPeriod_019f8fe2-1fcb-79d5-b27d-eeac7b493fcf" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GoodwillAcquiredDuringPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_019f8fe2-1fcb-7bcb-bc00-ad23a356a2c0" xlink:to="loc_us-gaap_GoodwillAcquiredDuringPeriod_019f8fe2-1fcb-79d5-b27d-eeac7b493fcf" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_019f8fe2-1fcb-757a-8c80-cb2ac435f352" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Goodwill"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.corp.kaltura.com/role/NETLOSSPERSHAREATTRIBUTABLETOCOMMONSTOCKHOLDERSScheduleofAntidilutiveSecuritiesExcludedfromComputationofEarningsPerShareDetails" xlink:type="simple" xlink:href="kltr-20260630.xsd#NETLOSSPERSHAREATTRIBUTABLETOCOMMONSTOCKHOLDERSScheduleofAntidilutiveSecuritiesExcludedfromComputationofEarningsPerShareDetails"/>
  <link:definitionLink xlink:role="http://www.corp.kaltura.com/role/NETLOSSPERSHAREATTRIBUTABLETOCOMMONSTOCKHOLDERSScheduleofAntidilutiveSecuritiesExcludedfromComputationofEarningsPerShareDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_019f6fac-7ec2-78ac-bd4b-ea61a2846032" 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_019f6fac-7ec2-72f2-91e1-01b919a3eaa2" 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_019f6fac-7ec2-78ac-bd4b-ea61a2846032" xlink:to="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_019f6fac-7ec2-72f2-91e1-01b919a3eaa2" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_019f6fac-7ec2-78fd-88c1-7bb552904a78" 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_019f6fac-7ec2-72f2-91e1-01b919a3eaa2" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_019f6fac-7ec2-78fd-88c1-7bb552904a78" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019f6fac-7ec2-78fd-88c1-7bb552904a78_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_019f6fac-7ec2-78fd-88c1-7bb552904a78" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019f6fac-7ec2-78fd-88c1-7bb552904a78_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019f6fac-7ec2-702d-917c-7c8e9e33a6f6" 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_019f6fac-7ec2-78fd-88c1-7bb552904a78" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019f6fac-7ec2-702d-917c-7c8e9e33a6f6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockCompensationPlanMember_019fa92a-191a-74a6-90d3-e3556beb5029" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockCompensationPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019f6fac-7ec2-702d-917c-7c8e9e33a6f6" xlink:to="loc_us-gaap_StockCompensationPlanMember_019fa92a-191a-74a6-90d3-e3556beb5029" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_019f6fac-7ec2-7548-a87b-6d02f12d2a98" 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_019f6fac-7ec2-78ac-bd4b-ea61a2846032" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_019f6fac-7ec2-7548-a87b-6d02f12d2a98" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.corp.kaltura.com/role/REPORTABLESEGMENTSANDGEOGRAPHICALINFORMATIONSegmentInformationDetails" xlink:type="simple" xlink:href="kltr-20260630.xsd#REPORTABLESEGMENTSANDGEOGRAPHICALINFORMATIONSegmentInformationDetails"/>
  <link:definitionLink xlink:role="http://www.corp.kaltura.com/role/REPORTABLESEGMENTSANDGEOGRAPHICALINFORMATIONSegmentInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_019f22d0-ec66-7d2d-b535-5107af6b57c8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019f22d0-ec66-7e7e-b4df-bbbef6eebbbe" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019f22d0-ec66-7d2d-b535-5107af6b57c8" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019f22d0-ec66-7e7e-b4df-bbbef6eebbbe" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019f22d0-ec66-7fc3-bdf7-6fcbafa12534" 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_ScheduleOfSegmentReportingInformationBySegmentTable_019f22d0-ec66-7e7e-b4df-bbbef6eebbbe" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019f22d0-ec66-7fc3-bdf7-6fcbafa12534" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019f22d0-ec66-7fc3-bdf7-6fcbafa12534_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_019f22d0-ec66-7fc3-bdf7-6fcbafa12534" xlink:to="loc_us-gaap_SegmentDomain_019f22d0-ec66-7fc3-bdf7-6fcbafa12534_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019f22d0-ec66-75e4-8cce-558df86fde4d" 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_019f22d0-ec66-7fc3-bdf7-6fcbafa12534" xlink:to="loc_us-gaap_SegmentDomain_019f22d0-ec66-75e4-8cce-558df86fde4d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_EnterpriseEducationAndTechnologySegmentMember_019f8f31-f920-752b-98e2-ac52f401cffe" xlink:href="kltr-20260630.xsd#kltr_EnterpriseEducationAndTechnologySegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f22d0-ec66-75e4-8cce-558df86fde4d" xlink:to="loc_kltr_EnterpriseEducationAndTechnologySegmentMember_019f8f31-f920-752b-98e2-ac52f401cffe" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_MediaAndTelecomSegmentMember_019f8f32-0efd-7a87-bd61-e7072dd1190b" xlink:href="kltr-20260630.xsd#kltr_MediaAndTelecomSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f22d0-ec66-75e4-8cce-558df86fde4d" xlink:to="loc_kltr_MediaAndTelecomSegmentMember_019f8f32-0efd-7a87-bd61-e7072dd1190b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019f22d0-ec66-7252-b602-5044f99959f2" 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_SegmentReportingInformationLineItems_019f22d0-ec66-7d2d-b535-5107af6b57c8" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019f22d0-ec66-7252-b602-5044f99959f2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfRevenueAbstract_019f599a-e610-70fc-b6ac-06c1448781c8" 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_SegmentReportingInformationLineItems_019f22d0-ec66-7d2d-b535-5107af6b57c8" xlink:to="loc_us-gaap_CostOfRevenueAbstract_019f599a-e610-70fc-b6ac-06c1448781c8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProductionAndDistributionCosts_019f22d0-ec66-76a4-b7d3-cf8652c82159" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProductionAndDistributionCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostOfRevenueAbstract_019f599a-e610-70fc-b6ac-06c1448781c8" xlink:to="loc_us-gaap_ProductionAndDistributionCosts_019f22d0-ec66-76a4-b7d3-cf8652c82159" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeBenefitsAndShareBasedCompensation_019f22d0-ec66-7f73-a404-4943399ba519" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeBenefitsAndShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostOfRevenueAbstract_019f599a-e610-70fc-b6ac-06c1448781c8" xlink:to="loc_us-gaap_EmployeeBenefitsAndShareBasedCompensation_019f22d0-ec66-7f73-a404-4943399ba519" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherDepreciationAndAmortization_019f8f32-a5ae-79da-bb07-dbe6988c06f6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherDepreciationAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostOfRevenueAbstract_019f599a-e610-70fc-b6ac-06c1448781c8" xlink:to="loc_us-gaap_OtherDepreciationAndAmortization_019f8f32-a5ae-79da-bb07-dbe6988c06f6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingOtherItemAmount_019f22d0-ec66-7fc9-b542-5a36a3d3362e" 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_CostOfRevenueAbstract_019f599a-e610-70fc-b6ac-06c1448781c8" xlink:to="loc_us-gaap_SegmentReportingOtherItemAmount_019f22d0-ec66-7fc9-b542-5a36a3d3362e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfGoodsAndServicesSold_019f22d0-ec66-77e9-8453-f1194c139d27" 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_019f599a-e610-70fc-b6ac-06c1448781c8" xlink:to="loc_us-gaap_CostOfGoodsAndServicesSold_019f22d0-ec66-77e9-8453-f1194c139d27" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GrossProfit_019f22d0-ec66-79e3-bf3a-49f410be20a6" 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_SegmentReportingInformationLineItems_019f22d0-ec66-7d2d-b535-5107af6b57c8" xlink:to="loc_us-gaap_GrossProfit_019f22d0-ec66-79e3-bf3a-49f410be20a6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpenses_019f22d0-ec66-7e65-845a-2c0b05bd4c7c" 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_SegmentReportingInformationLineItems_019f22d0-ec66-7d2d-b535-5107af6b57c8" xlink:to="loc_us-gaap_OperatingExpenses_019f22d0-ec66-7e65-845a-2c0b05bd4c7c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonoperatingIncomeExpense_019f22d0-ec66-7277-a13a-03d50304112f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NonoperatingIncomeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019f22d0-ec66-7d2d-b535-5107af6b57c8" xlink:to="loc_us-gaap_NonoperatingIncomeExpense_019f22d0-ec66-7277-a13a-03d50304112f" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_019f22d0-ec66-7095-8b2b-1d11c99c91b4" 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_SegmentReportingInformationLineItems_019f22d0-ec66-7d2d-b535-5107af6b57c8" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_019f22d0-ec66-7095-8b2b-1d11c99c91b4" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019f22d0-ec66-7740-aa0c-5d9837d47943" 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_SegmentReportingInformationLineItems_019f22d0-ec66-7d2d-b535-5107af6b57c8" xlink:to="loc_us-gaap_NetIncomeLoss_019f22d0-ec66-7740-aa0c-5d9837d47943" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.corp.kaltura.com/role/LONGTERMLOANNarrativeDetails" xlink:type="simple" xlink:href="kltr-20260630.xsd#LONGTERMLOANNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.corp.kaltura.com/role/LONGTERMLOANNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityLineItems_019f6fc6-ae4c-71bd-bf08-7972780f9e2f" 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_019f6fc6-ae4c-78af-a597-c1b7b379c9da" 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_019f6fc6-ae4c-71bd-bf08-7972780f9e2f" xlink:to="loc_us-gaap_LineOfCreditFacilityTable_019f6fc6-ae4c-78af-a597-c1b7b379c9da" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_019f6fc6-ae4c-714b-a07a-c044c2501acb" 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_019f6fc6-ae4c-78af-a597-c1b7b379c9da" xlink:to="loc_us-gaap_CreditFacilityAxis_019f6fc6-ae4c-714b-a07a-c044c2501acb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019f6fc6-ae4c-714b-a07a-c044c2501acb_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_019f6fc6-ae4c-714b-a07a-c044c2501acb" xlink:to="loc_us-gaap_CreditFacilityDomain_019f6fc6-ae4c-714b-a07a-c044c2501acb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019f6fc6-ae4c-71b3-9b2f-22ad4c9df377" 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_019f6fc6-ae4c-714b-a07a-c044c2501acb" xlink:to="loc_us-gaap_CreditFacilityDomain_019f6fc6-ae4c-71b3-9b2f-22ad4c9df377" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebtMember_019f6fc6-ae4c-7bd0-b1ab-3eb4bea84941" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_019f6fc6-ae4c-71b3-9b2f-22ad4c9df377" xlink:to="loc_us-gaap_SecuredDebtMember_019f6fc6-ae4c-7bd0-b1ab-3eb4bea84941" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_019f6fc6-ae4c-7834-821d-ed466851bcc2" 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_019f6fc6-ae4c-71b3-9b2f-22ad4c9df377" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_019f6fc6-ae4c-7834-821d-ed466851bcc2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_019f6fc6-ae4c-7750-b65a-ca65daca52b3" 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_019f6fc6-ae4c-78af-a597-c1b7b379c9da" xlink:to="loc_us-gaap_DebtInstrumentAxis_019f6fc6-ae4c-7750-b65a-ca65daca52b3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019f6fc6-ae4c-7750-b65a-ca65daca52b3_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_019f6fc6-ae4c-7750-b65a-ca65daca52b3" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019f6fc6-ae4c-7750-b65a-ca65daca52b3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019f6fc6-ae4c-7abc-a39d-f9354856cb05" 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_019f6fc6-ae4c-7750-b65a-ca65daca52b3" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019f6fc6-ae4c-7abc-a39d-f9354856cb05" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_TermLoanFacilityMember_019f6fc6-ae4c-7f0b-951d-97d9f7e1c538" xlink:href="kltr-20260630.xsd#kltr_TermLoanFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019f6fc6-ae4c-7abc-a39d-f9354856cb05" xlink:to="loc_kltr_TermLoanFacilityMember_019f6fc6-ae4c-7f0b-951d-97d9f7e1c538" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_TheRevolvingCreditFacilityMember_019f6fc6-ae4c-72ce-8d33-346c4ac04701" xlink:href="kltr-20260630.xsd#kltr_TheRevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019f6fc6-ae4c-7abc-a39d-f9354856cb05" xlink:to="loc_kltr_TheRevolvingCreditFacilityMember_019f6fc6-ae4c-72ce-8d33-346c4ac04701" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_CreditAgreementMember_019f6fc6-ae4c-7fbd-84e5-f21c641c62a2" xlink:href="kltr-20260630.xsd#kltr_CreditAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019f6fc6-ae4c-7abc-a39d-f9354856cb05" xlink:to="loc_kltr_CreditAgreementMember_019f6fc6-ae4c-7fbd-84e5-f21c641c62a2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_019f6fc6-ae4c-72e8-84b4-781da060fb7c" 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_019f6fc6-ae4c-78af-a597-c1b7b379c9da" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_019f6fc6-ae4c-72e8-84b4-781da060fb7c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019f6fc6-ae4c-72e8-84b4-781da060fb7c_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_019f6fc6-ae4c-72e8-84b4-781da060fb7c" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019f6fc6-ae4c-72e8-84b4-781da060fb7c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019f6fc6-ae4c-7b65-8927-f9ea346da271" 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_019f6fc6-ae4c-72e8-84b4-781da060fb7c" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019f6fc6-ae4c-7b65-8927-f9ea346da271" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_019f6fc6-ae4c-71c8-ae49-7d0fa3221bc4" 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_019f6fc6-ae4c-7b65-8927-f9ea346da271" xlink:to="loc_us-gaap_LineOfCreditMember_019f6fc6-ae4c-71c8-ae49-7d0fa3221bc4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateAxis_019f6fc6-ae4c-757b-9170-ab71c84ecdad" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_VariableRateAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_019f6fc6-ae4c-78af-a597-c1b7b379c9da" xlink:to="loc_us-gaap_VariableRateAxis_019f6fc6-ae4c-757b-9170-ab71c84ecdad" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_019f6fc6-ae4c-757b-9170-ab71c84ecdad_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VariableRateAxis_019f6fc6-ae4c-757b-9170-ab71c84ecdad" xlink:to="loc_us-gaap_VariableRateDomain_019f6fc6-ae4c-757b-9170-ab71c84ecdad_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_019f6fc6-ae4c-7a1c-a342-24018a347525" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VariableRateAxis_019f6fc6-ae4c-757b-9170-ab71c84ecdad" xlink:to="loc_us-gaap_VariableRateDomain_019f6fc6-ae4c-7a1c-a342-24018a347525" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EurodollarMember_019f6fc6-ae4c-7be7-9ac1-f1055407aac5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EurodollarMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_019f6fc6-ae4c-7a1c-a342-24018a347525" xlink:to="loc_us-gaap_EurodollarMember_019f6fc6-ae4c-7be7-9ac1-f1055407aac5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_AlternateBaseRateMember_019f6fc6-ae4c-7197-953f-d8a4da3ab268" xlink:href="kltr-20260630.xsd#kltr_AlternateBaseRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_019f6fc6-ae4c-7a1c-a342-24018a347525" xlink:to="loc_kltr_AlternateBaseRateMember_019f6fc6-ae4c-7197-953f-d8a4da3ab268" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember_019f6fc6-ae4c-75b2-9b9e-c696207a5ea5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_019f6fc6-ae4c-7a1c-a342-24018a347525" xlink:to="loc_us-gaap_SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember_019f6fc6-ae4c-75b2-9b9e-c696207a5ea5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_AdjustedTermSecuredOvernightFinancingRateMember_019f6fc6-ae4c-7aee-b64c-ab291f6a8ce7" xlink:href="kltr-20260630.xsd#kltr_AdjustedTermSecuredOvernightFinancingRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_019f6fc6-ae4c-7a1c-a342-24018a347525" xlink:to="loc_kltr_AdjustedTermSecuredOvernightFinancingRateMember_019f6fc6-ae4c-7aee-b64c-ab291f6a8ce7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_AlternateBaseRateFederalFundsEffectiveRateMember_019f6fc6-ae4c-7ca4-8194-f7a353d72a39" xlink:href="kltr-20260630.xsd#kltr_AlternateBaseRateFederalFundsEffectiveRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_019f6fc6-ae4c-7a1c-a342-24018a347525" xlink:to="loc_kltr_AlternateBaseRateFederalFundsEffectiveRateMember_019f6fc6-ae4c-7ca4-8194-f7a353d72a39" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_InstallmentPaymentDateAxis_019f6fc6-ae4c-7033-961b-aff1827ce1de" xlink:href="kltr-20260630.xsd#kltr_InstallmentPaymentDateAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_019f6fc6-ae4c-78af-a597-c1b7b379c9da" xlink:to="loc_kltr_InstallmentPaymentDateAxis_019f6fc6-ae4c-7033-961b-aff1827ce1de" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_InstallmentPaymentDateDomain_019f6fc6-ae4c-7033-961b-aff1827ce1de_default" xlink:href="kltr-20260630.xsd#kltr_InstallmentPaymentDateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_kltr_InstallmentPaymentDateAxis_019f6fc6-ae4c-7033-961b-aff1827ce1de" xlink:to="loc_kltr_InstallmentPaymentDateDomain_019f6fc6-ae4c-7033-961b-aff1827ce1de_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_InstallmentPaymentDateDomain_019f6fc6-ae4c-70ee-8549-dc9c8e8e005e" xlink:href="kltr-20260630.xsd#kltr_InstallmentPaymentDateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_kltr_InstallmentPaymentDateAxis_019f6fc6-ae4c-7033-961b-aff1827ce1de" xlink:to="loc_kltr_InstallmentPaymentDateDomain_019f6fc6-ae4c-70ee-8549-dc9c8e8e005e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_PeriodPaymentPeriod1Member_019f6fc6-ae4c-7b98-a779-08ca3a8edd6e" xlink:href="kltr-20260630.xsd#kltr_PeriodPaymentPeriod1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_kltr_InstallmentPaymentDateDomain_019f6fc6-ae4c-70ee-8549-dc9c8e8e005e" xlink:to="loc_kltr_PeriodPaymentPeriod1Member_019f6fc6-ae4c-7b98-a779-08ca3a8edd6e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_PeriodPaymentPeriod2Member_019f6fc6-ae4c-739f-ae6c-a7623802b042" xlink:href="kltr-20260630.xsd#kltr_PeriodPaymentPeriod2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_kltr_InstallmentPaymentDateDomain_019f6fc6-ae4c-70ee-8549-dc9c8e8e005e" xlink:to="loc_kltr_PeriodPaymentPeriod2Member_019f6fc6-ae4c-739f-ae6c-a7623802b042" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_PeriodPaymentPeriod3Member_019f9043-62b0-7492-aae8-8633fed361d7" xlink:href="kltr-20260630.xsd#kltr_PeriodPaymentPeriod3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_kltr_InstallmentPaymentDateDomain_019f6fc6-ae4c-70ee-8549-dc9c8e8e005e" xlink:to="loc_kltr_PeriodPaymentPeriod3Member_019f9043-62b0-7492-aae8-8633fed361d7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_PeriodPaymentPeriod4Member_019f6fc6-ae4c-72e6-be14-a4454282b497" xlink:href="kltr-20260630.xsd#kltr_PeriodPaymentPeriod4Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_kltr_InstallmentPaymentDateDomain_019f6fc6-ae4c-70ee-8549-dc9c8e8e005e" xlink:to="loc_kltr_PeriodPaymentPeriod4Member_019f6fc6-ae4c-72e6-be14-a4454282b497" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_019f6fc6-ae4c-794c-b99c-2ef040678c70" 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_019f6fc6-ae4c-71bd-bf08-7972780f9e2f" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_019f6fc6-ae4c-794c-b99c-2ef040678c70" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_019f6fc6-ae4c-7778-887a-d44395717bb0" 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_019f6fc6-ae4c-71bd-bf08-7972780f9e2f" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_019f6fc6-ae4c-7778-887a-d44395717bb0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_019f6fc6-ae4c-7ef9-9518-f9f2ff1e9b08" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_019f6fc6-ae4c-71bd-bf08-7972780f9e2f" xlink:to="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_019f6fc6-ae4c-7ef9-9518-f9f2ff1e9b08" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_DebtInstrumentPermittedRestrictedPaymentsAggregateAmount_019f8f19-f390-7187-8372-0913aeee2e88" xlink:href="kltr-20260630.xsd#kltr_DebtInstrumentPermittedRestrictedPaymentsAggregateAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_019f6fc6-ae4c-71bd-bf08-7972780f9e2f" xlink:to="loc_kltr_DebtInstrumentPermittedRestrictedPaymentsAggregateAmount_019f8f19-f390-7187-8372-0913aeee2e88" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_DebtInstrumentBasisSpreadOnVariableRateFloor_019f6fc6-ae4c-7ec5-b9b2-a362e776d58d" xlink:href="kltr-20260630.xsd#kltr_DebtInstrumentBasisSpreadOnVariableRateFloor"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_019f6fc6-ae4c-71bd-bf08-7972780f9e2f" xlink:to="loc_kltr_DebtInstrumentBasisSpreadOnVariableRateFloor_019f6fc6-ae4c-7ec5-b9b2-a362e776d58d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd_019f6fc6-ae4c-7797-b2ca-63b22f41ba6c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_019f6fc6-ae4c-71bd-bf08-7972780f9e2f" xlink:to="loc_us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd_019f6fc6-ae4c-7797-b2ca-63b22f41ba6c" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentPeriodicPayment_019f6fc6-ae4c-74c2-bbbe-9d46c7c99889" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentPeriodicPayment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_019f6fc6-ae4c-71bd-bf08-7972780f9e2f" xlink:to="loc_us-gaap_DebtInstrumentPeriodicPayment_019f6fc6-ae4c-74c2-bbbe-9d46c7c99889" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.corp.kaltura.com/role/STOCKHOLDERSEQUITYANDEQUITYINCENTIVEPLANSNarrativeDetails" xlink:type="simple" xlink:href="kltr-20260630.xsd#STOCKHOLDERSEQUITYANDEQUITYINCENTIVEPLANSNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.corp.kaltura.com/role/STOCKHOLDERSEQUITYANDEQUITYINCENTIVEPLANSNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_019f6fdb-b00e-79f5-b0b2-2ecd8331d654" 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_019f6fdb-b00e-752c-a462-690b412c2dd1" 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_019f6fdb-b00e-79f5-b0b2-2ecd8331d654" xlink:to="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_019f6fdb-b00e-752c-a462-690b412c2dd1" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis_019f6fdb-b00e-7363-8e3f-52ce9a128328" 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_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_019f6fdb-b00e-752c-a462-690b412c2dd1" xlink:to="loc_us-gaap_PlanNameAxis_019f6fdb-b00e-7363-8e3f-52ce9a128328" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_019f6fdb-b00e-7363-8e3f-52ce9a128328_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_019f6fdb-b00e-7363-8e3f-52ce9a128328" xlink:to="loc_us-gaap_PlanNameDomain_019f6fdb-b00e-7363-8e3f-52ce9a128328_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_019f6fdb-b00e-7312-b225-59467f47e4e3" 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_019f6fdb-b00e-7363-8e3f-52ce9a128328" xlink:to="loc_us-gaap_PlanNameDomain_019f6fdb-b00e-7312-b225-59467f47e4e3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_A2021PlanMember_019f6fdb-b00e-7c56-8718-1b6c370fc849" xlink:href="kltr-20260630.xsd#kltr_A2021PlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_019f6fdb-b00e-7312-b225-59467f47e4e3" xlink:to="loc_kltr_A2021PlanMember_019f6fdb-b00e-7c56-8718-1b6c370fc849" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_CommonStockCapitalSharesReservedForFutureIssuanceIncreaseDecrease_019f6fdb-b00e-7fad-a73c-7eba7afd1533" xlink:href="kltr-20260630.xsd#kltr_CommonStockCapitalSharesReservedForFutureIssuanceIncreaseDecrease"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_019f6fdb-b00e-79f5-b0b2-2ecd8331d654" xlink:to="loc_kltr_CommonStockCapitalSharesReservedForFutureIssuanceIncreaseDecrease_019f6fdb-b00e-7fad-a73c-7eba7afd1533" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_019f6fdb-b00e-7c47-aa81-8bfc5ecc2886" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_019f6fdb-b00e-79f5-b0b2-2ecd8331d654" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_019f6fdb-b00e-7c47-aa81-8bfc5ecc2886" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_019f6fdb-b00e-71bd-a380-c4644d632a02" 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_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_019f6fdb-b00e-79f5-b0b2-2ecd8331d654" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_019f6fdb-b00e-71bd-a380-c4644d632a02" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.corp.kaltura.com/role/STOCKHOLDERSEQUITYANDEQUITYINCENTIVEPLANSScheduleofRSUActivityDetails" xlink:type="simple" xlink:href="kltr-20260630.xsd#STOCKHOLDERSEQUITYANDEQUITYINCENTIVEPLANSScheduleofRSUActivityDetails"/>
  <link:definitionLink xlink:role="http://www.corp.kaltura.com/role/STOCKHOLDERSEQUITYANDEQUITYINCENTIVEPLANSScheduleofRSUActivityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockLineItems_019f6fd5-952c-7c2f-970a-d9211a845576" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfStockByClassTable_019f6fd5-952c-7edf-941b-fcaa15b843d3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfStockByClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ClassOfStockLineItems_019f6fd5-952c-7c2f-970a-d9211a845576" xlink:to="loc_us-gaap_ScheduleOfStockByClassTable_019f6fd5-952c-7edf-941b-fcaa15b843d3" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019f6fd5-952c-7693-bdd5-fb7167d07515" 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_ScheduleOfStockByClassTable_019f6fd5-952c-7edf-941b-fcaa15b843d3" xlink:to="loc_us-gaap_AwardTypeAxis_019f6fd5-952c-7693-bdd5-fb7167d07515" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f6fd5-952c-7693-bdd5-fb7167d07515_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_019f6fd5-952c-7693-bdd5-fb7167d07515" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f6fd5-952c-7693-bdd5-fb7167d07515_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f6fd5-952c-7417-8750-5ce2dcbe9a59" 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_019f6fd5-952c-7693-bdd5-fb7167d07515" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f6fd5-952c-7417-8750-5ce2dcbe9a59" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_019f6fd5-952c-7d76-8682-452e7ed2a1e5" 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_019f6fd5-952c-7417-8750-5ce2dcbe9a59" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_019f6fd5-952c-7d76-8682-452e7ed2a1e5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019f6fd5-952c-7f06-90b5-a54b139b207c" 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_ClassOfStockLineItems_019f6fd5-952c-7c2f-970a-d9211a845576" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019f6fd5-952c-7f06-90b5-a54b139b207c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019f6fd5-952c-7826-ba06-cace7f9eacd2" 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_019f6fd5-952c-7f06-90b5-a54b139b207c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019f6fd5-952c-7826-ba06-cace7f9eacd2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_019f6fd5-952c-7e45-b269-ad83046eece3" 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_019f6fd5-952c-7f06-90b5-a54b139b207c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_019f6fd5-952c-7e45-b269-ad83046eece3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_019f6fd5-952c-7ee5-ae8c-7f4adbdb4701" 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_019f6fd5-952c-7f06-90b5-a54b139b207c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_019f6fd5-952c-7ee5-ae8c-7f4adbdb4701" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_019f6fd5-952c-760b-9a27-49f378c4eb3a" 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_019f6fd5-952c-7f06-90b5-a54b139b207c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_019f6fd5-952c-760b-9a27-49f378c4eb3a" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019f6fd5-952c-70e6-985c-c3fcd0a55af2" 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_019f6fd5-952c-7084-a59d-12933fefe0da" 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_ClassOfStockLineItems_019f6fd5-952c-7c2f-970a-d9211a845576" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019f6fd5-952c-7084-a59d-12933fefe0da" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019f6fd5-952c-7939-9dae-b2d69d295ae4" 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_019f6fd5-952c-7084-a59d-12933fefe0da" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019f6fd5-952c-7939-9dae-b2d69d295ae4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_019f6fd5-952c-7e63-9752-13af4fe78dcf" 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_019f6fd5-952c-7084-a59d-12933fefe0da" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_019f6fd5-952c-7e63-9752-13af4fe78dcf" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_019f6fd5-952c-7a11-b30f-39c9e713e7a1" 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_019f6fd5-952c-7084-a59d-12933fefe0da" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_019f6fd5-952c-7a11-b30f-39c9e713e7a1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_019f6fd5-952c-795e-ad9a-3b591e155f14" 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_019f6fd5-952c-7084-a59d-12933fefe0da" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_019f6fd5-952c-795e-ad9a-3b591e155f14" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019f6fd5-952c-7500-a9cd-a96bf3bee490" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.corp.kaltura.com/role/STOCKHOLDERSEQUITYANDEQUITYINCENTIVEPLANSScheduleofStockbasedCompensationExpenseDetails" xlink:type="simple" xlink:href="kltr-20260630.xsd#STOCKHOLDERSEQUITYANDEQUITYINCENTIVEPLANSScheduleofStockbasedCompensationExpenseDetails"/>
  <link:definitionLink xlink:role="http://www.corp.kaltura.com/role/STOCKHOLDERSEQUITYANDEQUITYINCENTIVEPLANSScheduleofStockbasedCompensationExpenseDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_019f6fd5-952c-71f1-9bb1-4857e4aecc72" 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_019f6fd5-952c-769c-9080-94e35bbbfe59" 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_019f6fd5-952c-71f1-9bb1-4857e4aecc72" xlink:to="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_019f6fd5-952c-769c-9080-94e35bbbfe59" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementOfIncomeLocationBalanceAxis_019f6fd5-952c-7a4e-ac54-72789c6f7f0e" 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_019f6fd5-952c-769c-9080-94e35bbbfe59" xlink:to="loc_us-gaap_StatementOfIncomeLocationBalanceAxis_019f6fd5-952c-7a4e-ac54-72789c6f7f0e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_019f6fd5-952c-7afb-87ec-f9fa305f786a" 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_019f6fd5-952c-71f1-9bb1-4857e4aecc72" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_019f6fd5-952c-7afb-87ec-f9fa305f786a" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.corp.kaltura.com/role/STOCKHOLDERSEQUITYANDEQUITYINCENTIVEPLANSScheduleofStockbasedCompensationExpenseDetails_1" xlink:type="simple" xlink:href="kltr-20260630.xsd#STOCKHOLDERSEQUITYANDEQUITYINCENTIVEPLANSScheduleofStockbasedCompensationExpenseDetails_1"/>
  <link:definitionLink xlink:role="http://www.corp.kaltura.com/role/STOCKHOLDERSEQUITYANDEQUITYINCENTIVEPLANSScheduleofStockbasedCompensationExpenseDetails_1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_019f6fd5-952c-71f1-9bb1-4857e4aecc72" 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_019f6fd5-952c-769c-9080-94e35bbbfe59" 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_019f6fd5-952c-71f1-9bb1-4857e4aecc72" xlink:to="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_019f6fd5-952c-769c-9080-94e35bbbfe59" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_019f6fd5-952c-7afb-87ec-f9fa305f786a" 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_019f6fd5-952c-71f1-9bb1-4857e4aecc72" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_019f6fd5-952c-7afb-87ec-f9fa305f786a" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.corp.kaltura.com/role/STOCKHOLDERSEQUITYANDEQUITYINCENTIVEPLANSScheduleofCommonStockReservedForFutureIssuanceDetails" xlink:type="simple" xlink:href="kltr-20260630.xsd#STOCKHOLDERSEQUITYANDEQUITYINCENTIVEPLANSScheduleofCommonStockReservedForFutureIssuanceDetails"/>
  <link:definitionLink xlink:role="http://www.corp.kaltura.com/role/STOCKHOLDERSEQUITYANDEQUITYINCENTIVEPLANSScheduleofCommonStockReservedForFutureIssuanceDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockLineItems_019f6fd5-952c-76cd-9ac1-cad47c73f0de" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfStockByClassTable_019f6fd5-952c-7078-b1d3-b9138b061b06" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfStockByClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ClassOfStockLineItems_019f6fd5-952c-76cd-9ac1-cad47c73f0de" xlink:to="loc_us-gaap_ScheduleOfStockByClassTable_019f6fd5-952c-7078-b1d3-b9138b061b06" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019f6fd5-952c-7d43-bf3b-0849e4ab6695" 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_ScheduleOfStockByClassTable_019f6fd5-952c-7078-b1d3-b9138b061b06" xlink:to="loc_us-gaap_AwardTypeAxis_019f6fd5-952c-7d43-bf3b-0849e4ab6695" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f6fd5-952c-7d43-bf3b-0849e4ab6695_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_019f6fd5-952c-7d43-bf3b-0849e4ab6695" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f6fd5-952c-7d43-bf3b-0849e4ab6695_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f6fd5-952c-7ed2-9627-ba37a9c5f9d0" 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_019f6fd5-952c-7d43-bf3b-0849e4ab6695" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f6fd5-952c-7ed2-9627-ba37a9c5f9d0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_019f6fd5-952c-7c63-942b-513bf043b97f" 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_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f6fd5-952c-7ed2-9627-ba37a9c5f9d0" xlink:to="loc_us-gaap_EmployeeStockOptionMember_019f6fd5-952c-7c63-942b-513bf043b97f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_019f6fd5-952c-7e4d-b17e-1116ca10939b" 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_019f6fd5-952c-7ed2-9627-ba37a9c5f9d0" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_019f6fd5-952c-7e4d-b17e-1116ca10939b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis_019f6fd5-952c-7eb2-a081-cad3a16a4dd7" 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_ScheduleOfStockByClassTable_019f6fd5-952c-7078-b1d3-b9138b061b06" xlink:to="loc_us-gaap_PlanNameAxis_019f6fd5-952c-7eb2-a081-cad3a16a4dd7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_019f6fd5-952c-7eb2-a081-cad3a16a4dd7_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_019f6fd5-952c-7eb2-a081-cad3a16a4dd7" xlink:to="loc_us-gaap_PlanNameDomain_019f6fd5-952c-7eb2-a081-cad3a16a4dd7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_019f6fd5-952c-7cbd-b351-53ae48e2cad4" 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_019f6fd5-952c-7eb2-a081-cad3a16a4dd7" xlink:to="loc_us-gaap_PlanNameDomain_019f6fd5-952c-7cbd-b351-53ae48e2cad4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_A2021PlanMember_019f6fd5-952c-78db-beec-51be7a8de244" xlink:href="kltr-20260630.xsd#kltr_A2021PlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_019f6fd5-952c-7cbd-b351-53ae48e2cad4" xlink:to="loc_kltr_A2021PlanMember_019f6fd5-952c-78db-beec-51be7a8de244" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_019f6fd5-952c-70ba-96bc-d76d99b2fa34" 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_ClassOfStockLineItems_019f6fd5-952c-76cd-9ac1-cad47c73f0de" xlink:to="loc_us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_019f6fd5-952c-70ba-96bc-d76d99b2fa34" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.corp.kaltura.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMEDetails" xlink:type="simple" xlink:href="kltr-20260630.xsd#ACCUMULATEDOTHERCOMPREHENSIVEINCOMEDetails"/>
  <link:definitionLink xlink:role="http://www.corp.kaltura.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMEDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_019f6fed-452a-7f79-a6f9-610962c015cc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_019f6fed-452a-7691-a306-539bb3a60efa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_019f6fed-452a-7f79-a6f9-610962c015cc" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_019f6fed-452a-7691-a306-539bb3a60efa" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_019f6fed-452a-7df5-9bfe-ea9dc1db4a26" 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_AccumulatedOtherComprehensiveIncomeLossTable_019f6fed-452a-7691-a306-539bb3a60efa" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_019f6fed-452a-7df5-9bfe-ea9dc1db4a26" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019f6fed-452a-7df5-9bfe-ea9dc1db4a26_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_019f6fed-452a-7df5-9bfe-ea9dc1db4a26" xlink:to="loc_us-gaap_EquityComponentDomain_019f6fed-452a-7df5-9bfe-ea9dc1db4a26_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019f6fed-452a-7611-9a50-7171443ed590" 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_019f6fed-452a-7df5-9bfe-ea9dc1db4a26" xlink:to="loc_us-gaap_EquityComponentDomain_019f6fed-452a-7611-9a50-7171443ed590" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019f6fed-452a-78ed-b01a-c2678d442e25" 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_019f6fed-452a-7611-9a50-7171443ed590" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019f6fed-452a-78ed-b01a-c2678d442e25" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember_019f6fed-452a-7339-b354-476331a0bf1f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019f6fed-452a-78ed-b01a-c2678d442e25" xlink:to="loc_us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember_019f6fed-452a-7339-b354-476331a0bf1f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_019f6fed-452a-7130-b9a3-896646e725e3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019f6fed-452a-78ed-b01a-c2678d442e25" xlink:to="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_019f6fed-452a-7130-b9a3-896646e725e3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_019f6fed-452a-7e8b-ac20-ed5e36d32a2b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AOCIAttributableToParentNetOfTaxRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_019f6fed-452a-7f79-a6f9-610962c015cc" xlink:to="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_019f6fed-452a-7e8b-ac20-ed5e36d32a2b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019f6fed-452a-72f5-8c52-3fe3d18278f7" 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_AOCIAttributableToParentNetOfTaxRollForward_019f6fed-452a-7e8b-ac20-ed5e36d32a2b" xlink:to="loc_us-gaap_StockholdersEquity_019f6fed-452a-72f5-8c52-3fe3d18278f7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OciBeforeReclassificationsNetOfTaxAttributableToParent_019f6fed-452a-709f-a4e9-ecf8bd652856" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OciBeforeReclassificationsNetOfTaxAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_019f6fed-452a-7e8b-ac20-ed5e36d32a2b" xlink:to="loc_us-gaap_OciBeforeReclassificationsNetOfTaxAttributableToParent_019f6fed-452a-709f-a4e9-ecf8bd652856" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent_019f6fed-452a-7012-8b64-60d94aae82ee" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_019f6fed-452a-7e8b-ac20-ed5e36d32a2b" xlink:to="loc_us-gaap_ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent_019f6fed-452a-7012-8b64-60d94aae82ee" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_019f6fed-452a-7e47-b617-41e67629db5b" 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_AOCIAttributableToParentNetOfTaxRollForward_019f6fed-452a-7e8b-ac20-ed5e36d32a2b" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_019f6fed-452a-7e47-b617-41e67629db5b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019f6fed-452a-7c57-8028-3202c75ed058" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.corp.kaltura.com/role/RESTRUCTURINGACTIVITIESNarrativeDetails" xlink:type="simple" xlink:href="kltr-20260630.xsd#RESTRUCTURINGACTIVITIESNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.corp.kaltura.com/role/RESTRUCTURINGACTIVITIESNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCostAndReserveLineItems_019f9061-0b53-7b15-a671-d48583f30da5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringCostAndReserveLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_019f9060-d772-7a43-93cf-7e16fcb14f57" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfRestructuringAndRelatedCostsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_019f9061-0b53-7b15-a671-d48583f30da5" xlink:to="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_019f9060-d772-7a43-93cf-7e16fcb14f57" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringPlanAxis_019fa919-6103-7843-ab6f-9ca020b5a0ce" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringPlanAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_019f9060-d772-7a43-93cf-7e16fcb14f57" xlink:to="loc_us-gaap_RestructuringPlanAxis_019fa919-6103-7843-ab6f-9ca020b5a0ce" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringPlanDomain_019fa919-6103-7843-ab6f-9ca020b5a0ce_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringPlanDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RestructuringPlanAxis_019fa919-6103-7843-ab6f-9ca020b5a0ce" xlink:to="loc_us-gaap_RestructuringPlanDomain_019fa919-6103-7843-ab6f-9ca020b5a0ce_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringPlanDomain_019fa919-6103-772a-bba4-ea6ca1162051" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringPlanDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RestructuringPlanAxis_019fa919-6103-7843-ab6f-9ca020b5a0ce" xlink:to="loc_us-gaap_RestructuringPlanDomain_019fa919-6103-772a-bba4-ea6ca1162051" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_PathFactoryRestructuringPlanMember_019fa91f-9c0a-7b2a-ba5f-7349d0c129f4" xlink:href="kltr-20260630.xsd#kltr_PathFactoryRestructuringPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringPlanDomain_019fa919-6103-772a-bba4-ea6ca1162051" xlink:to="loc_kltr_PathFactoryRestructuringPlanMember_019fa91f-9c0a-7b2a-ba5f-7349d0c129f4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_A2026ReorganizationPlanMember_019fa91a-2cb2-79e3-94cd-bd1699a4ffae" xlink:href="kltr-20260630.xsd#kltr_A2026ReorganizationPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringPlanDomain_019fa919-6103-772a-bba4-ea6ca1162051" xlink:to="loc_kltr_A2026ReorganizationPlanMember_019fa91a-2cb2-79e3-94cd-bd1699a4ffae" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCostAndReserveAxis_019f9061-30b1-70ad-b219-d7ff7389adce" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringCostAndReserveAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_019f9060-d772-7a43-93cf-7e16fcb14f57" xlink:to="loc_us-gaap_RestructuringCostAndReserveAxis_019f9061-30b1-70ad-b219-d7ff7389adce" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TypeOfRestructuringDomain_019f9061-30b1-70ad-b219-d7ff7389adce_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TypeOfRestructuringDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RestructuringCostAndReserveAxis_019f9061-30b1-70ad-b219-d7ff7389adce" xlink:to="loc_us-gaap_TypeOfRestructuringDomain_019f9061-30b1-70ad-b219-d7ff7389adce_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TypeOfRestructuringDomain_019f9061-30b1-7236-9857-6594ef46f809" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TypeOfRestructuringDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RestructuringCostAndReserveAxis_019f9061-30b1-70ad-b219-d7ff7389adce" xlink:to="loc_us-gaap_TypeOfRestructuringDomain_019f9061-30b1-7236-9857-6594ef46f809" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeSeveranceMember_019fa38a-b73f-7d6c-82a6-435da7cd849a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeSeveranceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfRestructuringDomain_019f9061-30b1-7236-9857-6594ef46f809" xlink:to="loc_us-gaap_EmployeeSeveranceMember_019fa38a-b73f-7d6c-82a6-435da7cd849a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringAndRelatedCostNumberOfPositionsEliminatedPeriodPercent_019f9052-1677-7b9c-8865-3f7d5f10ec7e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringAndRelatedCostNumberOfPositionsEliminatedPeriodPercent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_019f9061-0b53-7b15-a671-d48583f30da5" xlink:to="loc_us-gaap_RestructuringAndRelatedCostNumberOfPositionsEliminatedPeriodPercent_019f9052-1677-7b9c-8865-3f7d5f10ec7e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCharges_019f9052-1677-7afb-91da-71ce58bd6a95" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringCharges"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_019f9061-0b53-7b15-a671-d48583f30da5" xlink:to="loc_us-gaap_RestructuringCharges_019f9052-1677-7afb-91da-71ce58bd6a95" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.corp.kaltura.com/role/RESTRUCTURINGACTIVITIESRestructuringLiabilityDetails" xlink:type="simple" xlink:href="kltr-20260630.xsd#RESTRUCTURINGACTIVITIESRestructuringLiabilityDetails"/>
  <link:definitionLink xlink:role="http://www.corp.kaltura.com/role/RESTRUCTURINGACTIVITIESRestructuringLiabilityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCostAndReserveLineItems_019f9052-1677-7fd8-8a1b-606853c9dd6b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringCostAndReserveLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_019f9052-1677-7f4c-9959-761047a84670" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfRestructuringAndRelatedCostsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_019f9052-1677-7fd8-8a1b-606853c9dd6b" xlink:to="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_019f9052-1677-7f4c-9959-761047a84670" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019f9052-1677-79cd-b2db-dd2a74e779d2" 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_ScheduleOfRestructuringAndRelatedCostsTable_019f9052-1677-7f4c-9959-761047a84670" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019f9052-1677-79cd-b2db-dd2a74e779d2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019f9052-1677-79cd-b2db-dd2a74e779d2_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_019f9052-1677-79cd-b2db-dd2a74e779d2" xlink:to="loc_us-gaap_SegmentDomain_019f9052-1677-79cd-b2db-dd2a74e779d2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019f9052-1677-791f-9679-70536c1059b9" 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_019f9052-1677-79cd-b2db-dd2a74e779d2" xlink:to="loc_us-gaap_SegmentDomain_019f9052-1677-791f-9679-70536c1059b9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_EnterpriseEducationAndTechnologySegmentMember_019f9052-1677-7327-88f5-1ffd0456f67f" xlink:href="kltr-20260630.xsd#kltr_EnterpriseEducationAndTechnologySegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f9052-1677-791f-9679-70536c1059b9" xlink:to="loc_kltr_EnterpriseEducationAndTechnologySegmentMember_019f9052-1677-7327-88f5-1ffd0456f67f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_kltr_MediaAndTelecomSegmentMember_019f9052-1677-7528-9d39-ece434f30477" xlink:href="kltr-20260630.xsd#kltr_MediaAndTelecomSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f9052-1677-791f-9679-70536c1059b9" xlink:to="loc_kltr_MediaAndTelecomSegmentMember_019f9052-1677-7528-9d39-ece434f30477" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringReserveRollForward_019f9052-1677-7ac9-a6fd-fc1f47cbb641" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringReserveRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_019f9052-1677-7fd8-8a1b-606853c9dd6b" xlink:to="loc_us-gaap_RestructuringReserveRollForward_019f9052-1677-7ac9-a6fd-fc1f47cbb641" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringReserve_019f9052-1677-768c-8387-7a745d1df478" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringReserve"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringReserveRollForward_019f9052-1677-7ac9-a6fd-fc1f47cbb641" xlink:to="loc_us-gaap_RestructuringReserve_019f9052-1677-768c-8387-7a745d1df478" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringReserveAccrualAdjustment1_019f9052-1677-7a37-bf08-f12fdf740804" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringReserveAccrualAdjustment1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringReserveRollForward_019f9052-1677-7ac9-a6fd-fc1f47cbb641" xlink:to="loc_us-gaap_RestructuringReserveAccrualAdjustment1_019f9052-1677-7a37-bf08-f12fdf740804" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForRestructuring_019f9052-1677-7357-b4f5-2c25b36f3e25" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsForRestructuring"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringReserveRollForward_019f9052-1677-7ac9-a6fd-fc1f47cbb641" xlink:to="loc_us-gaap_PaymentsForRestructuring_019f9052-1677-7357-b4f5-2c25b36f3e25" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringReserve_019f9052-1677-7421-a784-5a598ca2acdb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringReserve"/>
  </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_kltr_EyalManorMember_019fb2af-c613-7ba5-b5ce-f301ce130c7b" xlink:href="kltr-20260630.xsd#kltr_EyalManorMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ecd_AllIndividualsMember" xlink:to="loc_kltr_EyalManorMember_019fb2af-c613-7ba5-b5ce-f301ce130c7b" xlink:type="arc" order="2"/>
  </link:definitionLink>
</link:linkbase>
