<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2024-11-05</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000104889</issuerCik>
        <issuerName>Graham Holdings Co</issuerName>
        <issuerTradingSymbol>GHC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001655513</rptOwnerCik>
            <rptOwnerName>Maas, Jacob</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O GRAHAM HOLDINGS COMPANY</rptOwnerStreet1>
            <rptOwnerStreet2>1300 NORTH 17TH STREET, SUITE 1700</rptOwnerStreet2>
            <rptOwnerCity>ARLINGTON</rptOwnerCity>
            <rptOwnerState>VA</rptOwnerState>
            <rptOwnerZipCode>22209</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Executive VP</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class B Common Stock</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2024-11-05</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F2"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1000</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                    <footnoteId id="F3"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4552</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">On January 19, 2022, the reporting person received a restricted stock unit award (Award) with price-based vesting conditions.  The terms of the Award provide that 1,000 shares vest if the issuer's Class B Common Stock's closing price meets or exceeds $700 for 90 consecutive calendar days on or before December 31, 2027, with an additional 1,000 shares vesting following each additional incremental increase of $100 in the closing price of the issuer's Class B Common Stock maintained for 90 consecutive days on or before December 31, 2027.  On November 5, 2024, the first 1,000 shares vested following achievement of the first stock price goal.</footnote>
        <footnote id="F2">Represents the second tranche of the Award, which will vest if the closing price of the issuer's Class B Common Stock exceeds  $800 for 90 consecutive calendar days on or before December 31, 2027. As noted above, if such price-based vesting condition is satisfied, the reporting person is eligible for vesting of additional 1,000 share increments of Class B Common Stock for each additional $100 increase in the closing price of the issuer's Class B Common Stock maintained for 90 consecutive days on or before December 31, 2027 (e.g., if the closing price of the issuer's Class B Common Stock exceeds $900 for 90 consecutive calendar days, then 1,000 additional shares of Class B Common stock will vest).</footnote>
        <footnote id="F3">N/A</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Nicole M. Maddrey for Jacob M. Maas</signatureName>
        <signatureDate>2024-11-08</signatureDate>
    </ownerSignature>
</ownershipDocument>
[{"type": "4", "sequence": "1", "filename": "wk-form4_1731100634.xml", "description": "FORM 4", "secsgml_size_bytes": 4697}]
X0508
4
2024-11-05
0
0000104889
Graham Holdings Co
GHC
0001655513
Maas, Jacob
C/O GRAHAM HOLDINGS COMPANY
1300 NORTH 17TH STREET, SUITE 1700
ARLINGTON
VA
22209
0
1
0
0
Executive VP
0
Class B Common Stock
2024-11-05
4
A
0
1000
0
A
4552
D
On January 19, 2022, the reporting person received a restricted stock unit award (Award) with price-based vesting conditions.  The terms of the Award provide that 1,000 shares vest if the issuer's Class B Common Stock's closing price meets or exceeds $700 for 90 consecutive calendar days on or before December 31, 2027, with an additional 1,000 shares vesting following each additional incremental increase of $100 in the closing price of the issuer's Class B Common Stock maintained for 90 consecutive days on or before December 31, 2027.  On November 5, 2024, the first 1,000 shares vested following achievement of the first stock price goal.
Represents the second tranche of the Award, which will vest if the closing price of the issuer's Class B Common Stock exceeds  $800 for 90 consecutive calendar days on or before December 31, 2027. As noted above, if such price-based vesting condition is satisfied, the reporting person is eligible for vesting of additional 1,000 share increments of Class B Common Stock for each additional $100 increase in the closing price of the issuer's Class B Common Stock maintained for 90 consecutive days on or before December 31, 2027 (e.g., if the closing price of the issuer's Class B Common Stock exceeds $900 for 90 consecutive calendar days, then 1,000 additional shares of Class B Common stock will vest).
N/A
Nicole M. Maddrey for Jacob M. Maas
2024-11-08