content: <?xml version="1.0" encoding="UTF-8"?><edgarSubmission xmlns="http://www.sec.gov/edgar/ownership" xmlns:com="http://www.sec.gov/edgar/common">
    <headerData>
      <submissionType>144</submissionType>
      <filerInfo>
        <filer>
          <filerCredentials>
            <cik>0001225110</cik>
            <ccc>XXXXXXXX</ccc>
          </filerCredentials>
        </filer>
        <liveTestFlag>LIVE</liveTestFlag>
  
  
      </filerInfo>
    </headerData>
    <formData>
      <issuerInfo>
        <issuerCik>0000883241</issuerCik>
        <issuerName>SYNOPSYS INC</issuerName>
        <secFileNumber>000-19807</secFileNumber>
        <issuerAddress>
          <com:street1>675 ALMANOR AVE</com:street1>
          <com:city>SUNNYVALE</com:city>
          <com:stateOrCountry>CA</com:stateOrCountry>
          <com:zipCode>94085</com:zipCode>
        </issuerAddress>
        <issuerContactPhone>6505845000</issuerContactPhone>
        <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>JOHNSON MERCEDES</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
        <relationshipsToIssuer>
          <relationshipToIssuer>Board Member</relationshipToIssuer>
        </relationshipsToIssuer>
      </issuerInfo>
      <securitiesInformation>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <brokerOrMarketmakerDetails>
          <name>Pershing Advisor Solutions</name>
          <address>
            <com:street1>One Pershing Plaza</com:street1>
            <com:city>JERSEY CITY</com:city>
            <com:stateOrCountry>NJ</com:stateOrCountry>
            <com:zipCode>07399</com:zipCode>
          </address>
        </brokerOrMarketmakerDetails>
        <noOfUnitsSold>5500</noOfUnitsSold>
        <aggregateMarketValue>3217500.00</aggregateMarketValue>
        <noOfUnitsOutstanding>152000054</noOfUnitsOutstanding>
        <approxSaleDate>05/28/2024</approxSaleDate>
        <securitiesExchangeName>NASDAQ</securitiesExchangeName>
      </securitiesInformation>
      <securitiesToBeSold>
        <securitiesClassTitle>common</securitiesClassTitle>
        <acquiredDate>04/11/2023</acquiredDate>
        <natureOfAcquisitionTransaction>RSU Vesting</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Mercedes Johnson</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>6383</amountOfSecuritiesAcquired>
        <paymentDate>04/11/2023</paymentDate>
        <natureOfPayment>Cash</natureOfPayment>
      </securitiesToBeSold>
      <nothingToReportFlagOnSecuritiesSoldInPast3Months>Y</nothingToReportFlagOnSecuritiesSoldInPast3Months>
      <noticeSignature>
        <noticeDate>05/28/2024</noticeDate>
        <signature>Mercedes Johnson</signature>
      </noticeSignature>
    </formData>
  </edgarSubmission>
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text: 144
  0001225110
  XXXXXXXX
  LIVE
  0000883241
  SYNOPSYS INC
  000-19807
  675 ALMANOR AVE
  SUNNYVALE
  CA
  94085
  6505845000
  JOHNSON MERCEDES
  Board Member
  Common
  Pershing Advisor Solutions
  One Pershing Plaza
  JERSEY CITY
  NJ
  07399
  5500
  3217500.00
  152000054
  05/28/2024
  NASDAQ
  common
  04/11/2023
  RSU Vesting
  Mercedes Johnson
  N
  6383
  04/11/2023
  Cash
  Y
  05/28/2024
  Mercedes Johnson