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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>0001140361-08-012771.txt : 20080515
<SEC-HEADER>0001140361-08-012771.hdr.sgml : 20080515
<ACCEPTANCE-DATETIME>20080515202448
ACCESSION NUMBER:		0001140361-08-012771
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20080515
FILED AS OF DATE:		20080515
DATE AS OF CHANGE:		20080515

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			U.S. Auto Parts Network, Inc.
		CENTRAL INDEX KEY:			0001378950
		STANDARD INDUSTRIAL CLASSIFICATION:	RETAIL-AUTO & HOME SUPPLY STORES [5531]
		IRS NUMBER:				680623433
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		17150 SOUTH MARGAY AVENUE
		CITY:			CARSON
		STATE:			CA
		ZIP:			90746
		BUSINESS PHONE:		(310) 715-6666

	MAIL ADDRESS:	
		STREET 1:		17150 SOUTH MARGAY AVENUE
		CITY:			CARSON
		STATE:			CA
		ZIP:			90746

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Berman Joshua L
		CENTRAL INDEX KEY:			0001415267

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-33264
		FILM NUMBER:		08840143

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		3107350085

	MAIL ADDRESS:	
		STREET 1:		C/O U.S. AUTO PARTS NETWORK, INC.
		STREET 2:		17150 SOUTH MARGAY AVENUE
		CITY:			CARSON
		STATE:			CA
		ZIP:			90746
</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>2008-05-15</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001378950</issuerCik>
        <issuerName>U.S. Auto Parts Network, Inc.</issuerName>
        <issuerTradingSymbol>PRTS</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001415267</rptOwnerCik>
            <rptOwnerName>Berman Joshua L</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O U.S. AUTO PARTS NETWORK, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>17150 SOUTH MARGAY AVENUE</rptOwnerStreet2>
            <rptOwnerCity>CARSON</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>90746</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2008-05-15</value>
            </transactionDate>
            <deemedExecutionDate>
                <value>2008-05-15</value>
            </deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>2600</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>3.5952</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2600</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes></footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Michael J. McClane, as Attorney-in-Fact for Joshua L. Berman</signatureName>
        <signatureDate>2008-05-15</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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