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

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2025-01-27</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>1812 NORTH MOORE STREET, SUITE 2100</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>2025-01-27</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>5725</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class B Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2025-01-27</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>438</value>
                    <footnoteId id="F4"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>918.26</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5287</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. On January 27, 2025, the second 1,000 shares vested following achievement of the second stock price goal.</footnote>
        <footnote id="F2">Represents the third tranche of the Award, which will vest if the closing price of the issuer's Class B Common Stock exceeds $900 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 $1,000 for 90 consecutive calendar days, then 1,000 additional shares of Class B Common stock will vest).</footnote>
        <footnote id="F3">N/A</footnote>
        <footnote id="F4">Represents withholding of Class B shares for the tax liability associated with the vesting and settlement of the restricted stock unit award referred to in footnote 1 above.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Nicole M. Maddrey, attorney-in-fact</signatureName>
        <signatureDate>2025-01-29</signatureDate>
    </ownerSignature>
</ownershipDocument>
[{"type": "4", "sequence": "1", "filename": "wk-form4_1738185699.xml", "description": "FORM 4", "secsgml_size_bytes": 6430}]
X0508
4
2025-01-27
0
0000104889
Graham Holdings Co
GHC
0001655513
Maas, Jacob
C/O GRAHAM HOLDINGS COMPANY
1812 NORTH MOORE STREET, SUITE 2100
ARLINGTON
VA
22209
0
1
0
0
Executive VP
0
Class B Common Stock
2025-01-27
4
A
0
1000
0
A
5725
D
Class B Common Stock
2025-01-27
4
F
0
438
918.26
D
5287
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. On January 27, 2025, the second 1,000 shares vested following achievement of the second stock price goal.
Represents the third tranche of the Award, which will vest if the closing price of the issuer's Class B Common Stock exceeds $900 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 $1,000 for 90 consecutive calendar days, then 1,000 additional shares of Class B Common stock will vest).
N/A
Represents withholding of Class B shares for the tax liability associated with the vesting and settlement of the restricted stock unit award referred to in footnote 1 above.
/s/ Nicole M. Maddrey, attorney-in-fact
2025-01-29