-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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<SEC-DOCUMENT>0001140361-08-000435.txt : 20080103
<SEC-HEADER>0001140361-08-000435.hdr.sgml : 20080103
<ACCEPTANCE-DATETIME>20080103200534
ACCESSION NUMBER:		0001140361-08-000435
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20080101
FILED AS OF DATE:		20080103
DATE AS OF CHANGE:		20080103

ISSUER:		

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

	BUSINESS ADDRESS:	
		STREET 1:		2511 GARDEN ROAD
		STREET 2:		BUILDING A SUITE 200
		CITY:			MONTEREY
		STATE:			CA
		ZIP:			93940
		BUSINESS PHONE:		3042736000

	MAIL ADDRESS:	
		STREET 1:		2511 GARDEN ROAD
		STREET 2:		BUILDING A SUITE 200
		CITY:			MONTEREY
		STATE:			CA
		ZIP:			93940

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Kruger Logan W
		CENTRAL INDEX KEY:			0001344865

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-27918
		FILM NUMBER:		08509007

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		8316429300

	MAIL ADDRESS:	
		STREET 1:		C/O CENTURY ALUMINUM COMPANY
		STREET 2:		2511 GARDEN ROAD, BUILDING A, SUITE 200
		CITY:			MONTEREY
		STATE:			CA
		ZIP:			93940
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc1.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2008-01-01</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001344865</rptOwnerCik>
            <rptOwnerName>Kruger Logan W</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>CENTURY ALUMINUM COMPANY</rptOwnerStreet1>
            <rptOwnerStreet2>2511 GARDEN ROAD, BLDG A, SUITE 200</rptOwnerStreet2>
            <rptOwnerCity>MONTEREY</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>93940</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President and CEO</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2008-01-01</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>9837</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>54.02</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>24919</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>123.31</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>401(k)</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Reports shares withheld by the Issuer to satisfy tax obligations at a net settlement price equal to the average of the high and low sales price on NASDAQ on December 31, 2007, the trading day immediately preceeding the vesting date as the vesting day occured on a day the markets were not open for trading, in connection with the shares of common stock granted to the Reporting Person on December 13, 2005, one-half of which vested on January 1, 2007 and the remaining one-half vested on January 1, 2008.  Such shares were granted to the Reporting Person pursuant to a Rule 16b-3(d) plan.</footnote>
        <footnote id="F2">Reported by 401(k) plan trustee as of January 2, 2008.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>William J. Leatherberry, Attorney-in-Fact for Logan W. Kruger</signatureName>
        <signatureDate>2008-01-03</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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