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

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2024-09-20</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000095953</issuerCik>
        <issuerName>ASCENT INDUSTRIES CO.</issuerName>
        <issuerTradingSymbol>ACNT</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0002034597</rptOwnerCik>
            <rptOwnerName>Pan Anthony X</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>11622 ASTER LANE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>WOODBURY</rptOwnerCity>
            <rptOwnerState>MN</rptOwnerState>
            <rptOwnerZipCode>55129</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>VP, Sales &amp; Bus. Development</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2024-09-20</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>2000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>9.42</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>10570</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">The reported price in column 4 is a weighted average purchase price. These shares were purchased in multiple transactions at prices ranging from $9.41 to $9.43 per share. The
Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchanges Commission, upon request, full information regarding the
number of shares purchased at each separate price within the range set forth within this footnote</footnote>
        <footnote id="F2">Reporting Person previously reported indirect holdings of 1,293 shares (by spouse) and 550 shares (by mother). Reporting Person disclaims beneficial ownership of such indirectly held securities. This report
shall not be deemed an admission that the reporting person is the beneficial owner of such securities for purpose of Section 16 or any other purpose.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Anthony X. Pan</signatureName>
        <signatureDate>2024-09-24</signatureDate>
    </ownerSignature>
</ownershipDocument>
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X0508
4
2024-09-20
0
0000095953
ASCENT INDUSTRIES CO.
ACNT
0002034597
Pan Anthony X
11622 ASTER LANE
WOODBURY
MN
55129
0
1
0
0
VP, Sales & Bus. Development
0
Common Stock
2024-09-20
4
P
0
2000
9.42
A
10570
D
The reported price in column 4 is a weighted average purchase price. These shares were purchased in multiple transactions at prices ranging from $9.41 to $9.43 per share. The
Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchanges Commission, upon request, full information regarding the
number of shares purchased at each separate price within the range set forth within this footnote
Reporting Person previously reported indirect holdings of 1,293 shares (by spouse) and 550 shares (by mother). Reporting Person disclaims beneficial ownership of such indirectly held securities. This report
shall not be deemed an admission that the reporting person is the beneficial owner of such securities for purpose of Section 16 or any other purpose.
Anthony X. Pan
2024-09-24