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        <filer>
          <filerCredentials>
            <cik>0001275602</cik>
            <ccc>XXXXXXXX</ccc>
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        <liveTestFlag>LIVE</liveTestFlag>
  
  
  
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        <issuerCik>0001049521</issuerCik>
        <issuerName>MERCURY SYSTEMS INC</issuerName>
        <secFileNumber>001-41194</secFileNumber>
        <issuerAddress>
          <com:street1>50 MINUTEMAN ROAD</com:street1>
          <com:city>ANDOVER</com:city>
          <com:stateOrCountry>MA</com:stateOrCountry>
          <com:zipCode>01810</com:zipCode>
        </issuerAddress>
        <issuerContactPhone>9782561300</issuerContactPhone>
        <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>CAMBRIA CHRISTOPHER C</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
        <relationshipsToIssuer>
          <relationshipToIssuer>Officer</relationshipToIssuer>
        </relationshipsToIssuer>
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      <securitiesInformation>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <brokerOrMarketmakerDetails>
          <name>Fidelity Brokerage Services LLC</name>
          <address>
            <com:street1>900 Salem Street</com:street1>
            <com:city>Smithfield</com:city>
            <com:stateOrCountry>RI</com:stateOrCountry>
            <com:zipCode>02917</com:zipCode>
          </address>
        </brokerOrMarketmakerDetails>
        <noOfUnitsSold>493</noOfUnitsSold>
        <aggregateMarketValue>18461.91</aggregateMarketValue>
        <noOfUnitsOutstanding>58189929</noOfUnitsOutstanding>
        <approxSaleDate>08/18/2023</approxSaleDate>
        <securitiesExchangeName>NASDAQ</securitiesExchangeName>
      </securitiesInformation>
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        <securitiesClassTitle>Common</securitiesClassTitle>
        <acquiredDate>08/17/2023</acquiredDate>
        <natureOfAcquisitionTransaction>Restricted Stock Vesting</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>493</amountOfSecuritiesAcquired>
        <paymentDate>08/17/2023</paymentDate>
        <natureOfPayment>Compensation</natureOfPayment>
      </securitiesToBeSold>
      <nothingToReportFlagOnSecuritiesSoldInPast3Months>N</nothingToReportFlagOnSecuritiesSoldInPast3Months>
      <securitiesSoldInPast3Months>
        <sellerDetails>
          <name>Christopher C. Cambria</name>
          <address>
            <com:street1>50 Minuteman Road</com:street1>
            <com:city>Andover</com:city>
            <com:stateOrCountry>MA</com:stateOrCountry>
            <com:zipCode>01810</com:zipCode>
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        <securitiesClassTitle>Common</securitiesClassTitle>
        <saleDate>08/17/2023</saleDate>
        <amountOfSecuritiesSold>712</amountOfSecuritiesSold>
        <grossProceeds>26225.67</grossProceeds>
      </securitiesSoldInPast3Months>
      <noticeSignature>
        <noticeDate>08/18/2023</noticeDate>
        <signature>/s/ Ryan Riviere, as a duly authorized representative of Fidelity Brokerage Services LLC, as attorney-in-fact for Christopher C. Cambria</signature>
      </noticeSignature>
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text: 144
  0001275602
  XXXXXXXX
  LIVE
  0001049521
  MERCURY SYSTEMS INC
  001-41194
  50 MINUTEMAN ROAD
  ANDOVER
  MA
  01810
  9782561300
  CAMBRIA CHRISTOPHER C
  Officer
  Common
  Fidelity Brokerage Services LLC
  900 Salem Street
  Smithfield
  RI
  02917
  493
  18461.91
  58189929
  08/18/2023
  NASDAQ
  Common
  08/17/2023
  Restricted Stock Vesting
  Issuer
  N
  493
  08/17/2023
  Compensation
  N
  Christopher C. Cambria
  50 Minuteman Road
  Andover
  MA
  01810
  Common
  08/17/2023
  712
  26225.67
  08/18/2023
  /s/ Ryan Riviere, as a duly authorized representative of Fidelity Brokerage Services LLC, as attorney-in-fact for Christopher C. Cambria