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      <filerInfo>
        <filer>
          <filerCredentials>
            <cik>0001325550</cik>
            <ccc>XXXXXXXX</ccc>
          </filerCredentials>
        </filer>
        <liveTestFlag>LIVE</liveTestFlag>
  
  
      </filerInfo>
    </headerData>
    <formData>
      <issuerInfo>
        <issuerCik>0000704532</issuerCik>
        <issuerName>ONTO INNOVATION INC.</issuerName>
        <secFileNumber>001-39110</secFileNumber>
        <issuerAddress>
          <com:street1>16 JONSPIN ROAD</com:street1>
          <com:city>WILMINGTON</com:city>
          <com:stateOrCountry>MA</com:stateOrCountry>
          <com:zipCode>01887</com:zipCode>
        </issuerAddress>
        <issuerContactPhone>9782536200</issuerContactPhone>
        <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>Plisinski Michael P</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
        <relationshipsToIssuer>
          <relationshipToIssuer>Officer</relationshipToIssuer>
        </relationshipsToIssuer>
      </issuerInfo>
      <securitiesInformation>
        <securitiesClassTitle>common</securitiesClassTitle>
        <brokerOrMarketmakerDetails>
          <name>Fidelity Brokerage Services LLC</name>
          <address>
            <com:street1>245 Summer Street</com:street1>
            <com:city>Boston</com:city>
            <com:stateOrCountry>MA</com:stateOrCountry>
            <com:zipCode>02110</com:zipCode>
          </address>
        </brokerOrMarketmakerDetails>
        <noOfUnitsSold>20000</noOfUnitsSold>
        <aggregateMarketValue>4003917.08</aggregateMarketValue>
        <noOfUnitsOutstanding>49391299</noOfUnitsOutstanding>
        <approxSaleDate>01/14/2025</approxSaleDate>
        <securitiesExchangeName>NYSE</securitiesExchangeName>
      </securitiesInformation>
      <securitiesToBeSold>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <acquiredDate>02/08/2021</acquiredDate>
        <natureOfAcquisitionTransaction>RSU</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>3266</amountOfSecuritiesAcquired>
        <paymentDate>02/08/2021</paymentDate>
        <natureOfPayment>N/A</natureOfPayment>
      </securitiesToBeSold>
      <securitiesToBeSold>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <acquiredDate>02/07/2021</acquiredDate>
        <natureOfAcquisitionTransaction>RSU</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>5751</amountOfSecuritiesAcquired>
        <paymentDate>02/07/2021</paymentDate>
        <natureOfPayment>N/A</natureOfPayment>
      </securitiesToBeSold>
      <securitiesToBeSold>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <acquiredDate>02/06/2021</acquiredDate>
        <natureOfAcquisitionTransaction>RSU	</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>3627</amountOfSecuritiesAcquired>
        <paymentDate>02/06/2021</paymentDate>
        <natureOfPayment>N/A</natureOfPayment>
      </securitiesToBeSold>
      <securitiesToBeSold>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <acquiredDate>01/27/2021</acquiredDate>
        <natureOfAcquisitionTransaction>RSU</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Issuer	</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>4600</amountOfSecuritiesAcquired>
        <paymentDate>01/27/2021</paymentDate>
        <natureOfPayment>N/A</natureOfPayment>
      </securitiesToBeSold>
      <securitiesToBeSold>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <acquiredDate>02/08/2020</acquiredDate>
        <natureOfAcquisitionTransaction>RSU	</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>2756</amountOfSecuritiesAcquired>
        <paymentDate>02/08/2020</paymentDate>
        <natureOfPayment>N/A</natureOfPayment>
      </securitiesToBeSold>
      <nothingToReportFlagOnSecuritiesSoldInPast3Months>Y</nothingToReportFlagOnSecuritiesSoldInPast3Months>
      <noticeSignature>
        <noticeDate>01/14/2025</noticeDate>
        <planAdoptionDates>
          <planAdoptionDate>08/26/2024</planAdoptionDate>
        </planAdoptionDates>
        <signature>/s/ Audrey Skillern as a duly authorized representative of Fidelity Brokerage Services LLC, as attorney-in-fact for Michael Plisinski </signature>
      </noticeSignature>
    </formData>
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text: 144
  0001325550
  XXXXXXXX
  LIVE
  0000704532
  ONTO INNOVATION INC.
  001-39110
  16 JONSPIN ROAD
  WILMINGTON
  MA
  01887
  9782536200
  Plisinski Michael P
  Officer
  common
  Fidelity Brokerage Services LLC
  245 Summer Street
  Boston
  MA
  02110
  20000
  4003917.08
  49391299
  01/14/2025
  NYSE
  Common
  02/08/2021
  RSU
  Issuer
  N
  3266
  02/08/2021
  N/A
  Common
  02/07/2021
  RSU
  Issuer
  N
  5751
  02/07/2021
  N/A
  Common
  02/06/2021
  RSU
  Issuer
  N
  3627
  02/06/2021
  N/A
  Common
  01/27/2021
  RSU
  Issuer
  N
  4600
  01/27/2021
  N/A
  Common
  02/08/2020
  RSU
  Issuer
  N
  2756
  02/08/2020
  N/A
  Y
  01/14/2025
  08/26/2024
  /s/ Audrey Skillern as a duly authorized representative of Fidelity Brokerage Services LLC, as attorney-in-fact for Michael Plisinski