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                    <ccc>XXXXXXXX</ccc>
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            <liveTestFlag>LIVE</liveTestFlag>



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        <issuerInfo>
            <issuerCik>0001097864</issuerCik>
            <issuerName>ON SEMICONDUCTOR CORP</issuerName>
            <secFileNumber>001-39317</secFileNumber>
            <issuerAddress>
                <ns2:street1>5005 East McDowell Road</ns2:street1>
                <ns2:city>Phoenix</ns2:city>
                <ns2:stateOrCountry>AZ</ns2:stateOrCountry>
                <ns2:zipCode>85008</ns2:zipCode>
            </issuerAddress>
            <issuerContactPhone>6022446600</issuerContactPhone>
            <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>EL-KHOURY LIVING TRUST U/T/A DTD01/16/2018</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
            <relationshipsToIssuer>
                <relationshipToIssuer>Officer</relationshipToIssuer>
            </relationshipsToIssuer>
        </issuerInfo>
        <securitiesInformation>
            <securitiesClassTitle>COMMON</securitiesClassTitle>
            <brokerOrMarketmakerDetails>
                <name>Morgan Stanley Smith Barney LLC Executive Financial Services</name>
                <address>
                    <ns2:street1>1 New York Plaza</ns2:street1>
                    <ns2:street2>38th Fl.</ns2:street2>
                    <ns2:city>New York</ns2:city>
                    <ns2:stateOrCountry>NY</ns2:stateOrCountry>
                    <ns2:zipCode>10004</ns2:zipCode>
                </address>
            </brokerOrMarketmakerDetails>
            <noOfUnitsSold>22500</noOfUnitsSold>
            <aggregateMarketValue>1990800.00</aggregateMarketValue>
            <noOfUnitsOutstanding>431873000</noOfUnitsOutstanding>
            <approxSaleDate>06/07/2023</approxSaleDate>
            <securitiesExchangeName>NASDAQ</securitiesExchangeName>
        </securitiesInformation>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>12/07/2021</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted Stock Units</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>22500</amountOfSecuritiesAcquired>
            <paymentDate>12/07/2021</paymentDate>
            <natureOfPayment>N/A</natureOfPayment>
        </securitiesToBeSold>
        <nothingToReportFlagOnSecuritiesSoldInPast3Months>N</nothingToReportFlagOnSecuritiesSoldInPast3Months>
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            <sellerDetails>
                <name>10b5-1 Sales Plan for HASSANE EL-KHOURY TTEEEL-KHOURY LIVING TRUST U/T/A DTD01/16/2018</name>
                <address>
                    <ns2:street1>5005 East McDowell Road</ns2:street1>
                    <ns2:city>Phoenix</ns2:city>
                    <ns2:stateOrCountry>AZ</ns2:stateOrCountry>
                    <ns2:zipCode>85008</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>05/15/2023</saleDate>
            <amountOfSecuritiesSold>5000</amountOfSecuritiesSold>
            <grossProceeds>408800.00</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>10b5-1 Sales Plan for HASSANE EL-KHOURY TTEEEL-KHOURY LIVING TRUST U/T/A DTD01/16/2018</name>
                <address>
                    <ns2:street1>5005 East McDowell Road</ns2:street1>
                    <ns2:city>Phoenix</ns2:city>
                    <ns2:stateOrCountry>AZ</ns2:stateOrCountry>
                    <ns2:zipCode>85008</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>04/17/2023</saleDate>
            <amountOfSecuritiesSold>5000</amountOfSecuritiesSold>
            <grossProceeds>385500.00</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>10b5-1 Sales Plan for HASSANE EL-KHOURY TTEEEL-KHOURY LIVING TRUST U/T/A DTD01/16/2018</name>
                <address>
                    <ns2:street1>5005 East McDowell Road</ns2:street1>
                    <ns2:city>Phoenix</ns2:city>
                    <ns2:stateOrCountry>AZ</ns2:stateOrCountry>
                    <ns2:zipCode>85008</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>03/15/2023</saleDate>
            <amountOfSecuritiesSold>5000</amountOfSecuritiesSold>
            <grossProceeds>395900.00</grossProceeds>
        </securitiesSoldInPast3Months>
        <remarks>shares acquired via RSU/PSU Acquisitions from 12/07/2021-02/15/2023</remarks>
        <noticeSignature>
            <noticeDate>06/07/2023</noticeDate>
            <planAdoptionDates>
                <planAdoptionDate>02/14/2023</planAdoptionDate>
            </planAdoptionDates>
            <signature>/s/ Hassane El-Khoury</signature>
        </noticeSignature>
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144
0001558882
XXXXXXXX
LIVE
0001097864
ON SEMICONDUCTOR CORP
001-39317
5005 East McDowell Road
Phoenix
AZ
85008
6022446600
EL-KHOURY LIVING TRUST U/T/A DTD01/16/2018
Officer
COMMON
Morgan Stanley Smith Barney LLC Executive Financial Services
1 New York Plaza
38th Fl.
New York
NY
10004
22500
1990800.00
431873000
06/07/2023
NASDAQ
Common
12/07/2021
Restricted Stock Units
Issuer
N
22500
12/07/2021
N/A
N
10b5-1 Sales Plan for HASSANE EL-KHOURY TTEEEL-KHOURY LIVING TRUST U/T/A DTD01/16/2018
5005 East McDowell Road
Phoenix
AZ
85008
Common
05/15/2023
5000
408800.00
10b5-1 Sales Plan for HASSANE EL-KHOURY TTEEEL-KHOURY LIVING TRUST U/T/A DTD01/16/2018
5005 East McDowell Road
Phoenix
AZ
85008
Common
04/17/2023
5000
385500.00
10b5-1 Sales Plan for HASSANE EL-KHOURY TTEEEL-KHOURY LIVING TRUST U/T/A DTD01/16/2018
5005 East McDowell Road
Phoenix
AZ
85008
Common
03/15/2023
5000
395900.00
shares acquired via RSU/PSU Acquisitions from 12/07/2021-02/15/2023
06/07/2023
02/14/2023
/s/ Hassane El-Khoury