<SUBMISSION>
<ACCESSION-NUMBER>0001179110-06-022133
<TYPE>3
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20061120
<FILING-DATE>20061121
<DATE-OF-FILING-DATE-CHANGE>20061121
<ISSUER>
<COMPANY-DATA>
<CONFORMED-NAME>Willdan Group, Inc.
<CIK>0001370450
<ASSIGNED-SIC>8711
<IRS-NUMBER>141951112
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<BUSINESS-ADDRESS>
<STREET1>2401 EAST KATELLA AVENUE, SUITE 300
<CITY>ANAHEIM
<STATE>CA
<ZIP>92806
<PHONE>800-424-9144
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>2401 EAST KATELLA AVENUE, SUITE 300
<CITY>ANAHEIM
<STATE>CA
<ZIP>92806
</MAIL-ADDRESS>
</ISSUER>
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>Lenocker W Tracy
<CIK>0001378180
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>3
<ACT>34
<FILE-NUMBER>001-33076
<FILM-NUMBER>061232128
</FILING-VALUES>
<BUSINESS-ADDRESS>
<PHONE>800-424-9144
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>2401 EAST KATELLA AVENUE
<STREET2>SUITE 300
<CITY>ANAHEIM
<STATE>CA
<ZIP>92806
</MAIL-ADDRESS>
</REPORTING-OWNER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>FORM 3 -
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2006-11-20</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001370450</issuerCik>
        <issuerName>Willdan Group, Inc.</issuerName>
        <issuerTradingSymbol>WLDN</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001378180</rptOwnerCik>
            <rptOwnerName>Lenocker W Tracy</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>2401 EAST KATELLA AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 300</rptOwnerStreet2>
            <rptOwnerCity>ANAHEIM</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>92806</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>200000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>The 1996 Tracy and Joanne Lenocker Family Trust</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes></footnotes>

    <ownerSignature>
        <signatureName>W. Tracy Lenocker</signatureName>
        <signatureDate>2006-11-20</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SUBMISSION>
