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

    <schemaVersion>X0607</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2026-05-26</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0000820318</issuerCik>
        <issuerName>COHERENT CORP.</issuerName>
        <issuerTradingSymbol>COHR</issuerTradingSymbol>
        <issuerForeignTradingSymbol></issuerForeignTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0002138361</rptOwnerCik>
            <rptOwnerName>Place Jeffrey B.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerNonUSAddressFlag>false</rptOwnerNonUSAddressFlag>
            <rptOwnerStreet1>C/O COHERENT CORP.</rptOwnerStreet1>
            <rptOwnerStreet2>5100 PATRICK HENRY DRIVE</rptOwnerStreet2>
            <rptOwnerCity>SANTA CLARA</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>95054</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>false</isDirector>
            <isOfficer>true</isOfficer>
            <isTenPercentOwner>false</isTenPercentOwner>
            <isOther>false</isOther>
            <officerTitle>Chief Supply Chain Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>19839</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Includes 314 shares acquired in non-reportable transactions through Coherent Corp.'s employee stock purchase plan.</footnote>
        <footnote id="F2">Includes 19,525 shares underlying restricted stock units granted to the reporting person (&quot;RSUs&quot;) under the Issuer's Omnibus Incentive Plan. Each of the RSUs represents a contingent right to receive one share of the Issuer's Common Stock upon settlement. 6,508 of such restricted stock units will vest on July 1, 2026, and the remaining 13,017 restricted stock units will vest in eight quarterly installments beginning October 1, 2026, in each case subject to the reporting person's continued service.</footnote>
    </footnotes>

    <remarks>See attached Exhibit 24 - Power of Attorney.</remarks>

    <ownerSignature>
        <signatureName>/s/ Chris Forrester, Attorney-in-fact for Jeffrey B. Place</signatureName>
        <signatureDate>2026-06-05</signatureDate>
    </ownerSignature>
</ownershipDocument>
