<SEC-DOCUMENT>0000949157-24-000057.txt : 20240605
<SEC-HEADER>0000949157-24-000057.hdr.sgml : 20240605
<ACCEPTANCE-DATETIME>20240605185017
ACCESSION NUMBER:		0000949157-24-000057
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20240603
FILED AS OF DATE:		20240605
DATE AS OF CHANGE:		20240605

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Olivier Tamla A
		CENTRAL INDEX KEY:			0001980269
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-34474
		FILM NUMBER:		241023381

	MAIL ADDRESS:	
		STREET 1:		CENTURY ALUMINUM COMPANY
		STREET 2:		1 S. WACKER DRIVE, SUITE 1000
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60606

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			CENTURY ALUMINUM CO
		CENTRAL INDEX KEY:			0000949157
		STANDARD INDUSTRIAL CLASSIFICATION:	PRIMARY PRODUCTION OF ALUMINUM [3334]
		ORGANIZATION NAME:           	04 Manufacturing
		IRS NUMBER:				133070826
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		1 SOUTH WACKER DRIVE
		STREET 2:		SUITE 1000
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60606
		BUSINESS PHONE:		3126963101

	MAIL ADDRESS:	
		STREET 1:		1 SOUTH WACKER DRIVE
		STREET 2:		SUITE 1000
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60606
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wk-form4_1717627809.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2024-06-03</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000949157</issuerCik>
        <issuerName>CENTURY ALUMINUM CO</issuerName>
        <issuerTradingSymbol>CENX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001980269</rptOwnerCik>
            <rptOwnerName>Olivier Tamla A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O CENTURY ALUMINUM COMPANY</rptOwnerStreet1>
            <rptOwnerStreet2>1 S. WACKER DRIVE, SUITE 1000</rptOwnerStreet2>
            <rptOwnerCity>CHICAGO</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60606</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2024-06-03</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>7070</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>21895</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Represents annual grant of time-vesting share units (&quot;TVSUs&quot;), all of which vest in full on the earlier of (i) the 12-month anniversary of the grant date, (ii) the date of the Issuer's next regular annual meeting of stockholders, or (iii) the occurrence of certain other events in accordance with the terms of the award.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Paul Sharobeem, as attorney in fact for Tamla A. Olivier</signatureName>
        <signatureDate>2024-06-05</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
