<ownershipDocument>
    <schemaVersion>X0101</schemaVersion>

    <documentType>4</documentType>
<periodOfReport>2003-07-03</periodOfReport>
<notSubjectToSection16>0</notSubjectToSection16>
    <issuer>
        <issuerCik>0001027324</issuerCik>
        <issuerName>MID-STATE BANCSHARES</issuerName>
        <issuerTradingSymbol>MDST</issuerTradingSymbol>
</issuer>
<reportingOwner><reportingOwnerId>
            <rptOwnerCik>0001198893</rptOwnerCik>
            <rptOwnerName>STATHOS JAMES G</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>  </rptOwnerStreet1>
            <rptOwnerStreet2>  </rptOwnerStreet2>
            <rptOwnerCity>  </rptOwnerCity>
            <rptOwnerState>  </rptOwnerState>
            <rptOwnerZipCode>  </rptOwnerZipCode>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>0</isDirector>
<isOfficer>1</isOfficer>
<isTenPercentOwner>0</isTenPercentOwner>
<isOther>0</isOther>
<officerTitle>Exec Vice President/CFO</officerTitle>
<otherText></otherText>
</reportingOwnerRelationship>
</reportingOwner>
<derivativeSecurity><securityTitle><value>Common Stock</value>
<footnoteId id="F1"></footnoteId>
</securityTitle>
<conversionOrExercisePrice><value>17.9350</value>
<footnoteId id="F2"></footnoteId>
</conversionOrExercisePrice>
<transactionDate><value>2003-07-14</value>
<footnoteId id="F3"></footnoteId>
</transactionDate>
<transactionCoding><transactionFormType>4</transactionFormType>
<transactionCode>J</transactionCode>
<equitySwapInvolved>0</equitySwapInvolved>
<footnoteId id="F4"></footnoteId>
</transactionCoding>
<transactionAmounts><transactionShares><value>2118</value>
<footnoteId id="F5"></footnoteId>
</transactionShares>
<transactionValue><value>17.9350</value>
<footnoteId id="F2"></footnoteId>
</transactionValue>
<transactionAcquiredDisposedCode><value>A</value>
</transactionAcquiredDisposedCode>
</transactionAmounts>
<exerciseDate><value>2000-07-14</value>
</exerciseDate>
<expirationDate><value>2009-07-14</value>
</expirationDate>
<underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value>
<footnoteId id="F1"></footnoteId>
</underlyingSecurityTitle>
<underlyingSecurityShares><value>12706</value>
</underlyingSecurityShares>
</underlyingSecurity>
<postTransactionAmounts><sharesOwnedFollowingTransaction><value>7132</value>
<footnoteId id="F4"></footnoteId>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature><directOrIndirectOwnership><value>I</value>
</directOrIndirectOwnership>
<natureOfOwnership><value>By Company</value>
</natureOfOwnership>
</ownershipNature>
</derivativeSecurity>
<derivativeSecurity><securityTitle><value>Common Stock</value>
<footnoteId id="F6"></footnoteId>
</securityTitle>
<conversionOrExercisePrice><value>17.9350</value>
<footnoteId id="F2"></footnoteId>
</conversionOrExercisePrice>
<transactionDate><value>2003-07-14</value>
<footnoteId id="F7"></footnoteId>
</transactionDate>
<transactionCoding><transactionFormType>4</transactionFormType>
<transactionCode>J</transactionCode>
<equitySwapInvolved>0</equitySwapInvolved>
<footnoteId id="F7"></footnoteId>
</transactionCoding>
<transactionAmounts><transactionShares><value>7882</value>
<footnoteId id="F5"></footnoteId>
</transactionShares>
<transactionValue><value>17.9350</value>
<footnoteId id="F2"></footnoteId>
</transactionValue>
<transactionAcquiredDisposedCode><value>A</value>
</transactionAcquiredDisposedCode>
</transactionAmounts>
<exerciseDate><value>2000-07-14</value>
</exerciseDate>
<expirationDate><value>2009-07-14</value>
</expirationDate>
<underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value>
<footnoteId id="F6"></footnoteId>
</underlyingSecurityTitle>
<underlyingSecurityShares><value>37294</value>
</underlyingSecurityShares>
</underlyingSecurity>
<postTransactionAmounts><sharesOwnedFollowingTransaction><value>32868</value>
<footnoteId id="F7"></footnoteId>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature><directOrIndirectOwnership><value>I</value>
</directOrIndirectOwnership>
<natureOfOwnership><value>By Company</value>
</natureOfOwnership>
</ownershipNature>
</derivativeSecurity>
<footnotes><footnote id="F1">Incentive Stock Option (right to buy).  50,000 shares granted as an ISO under the Company's 1996 Stock Option Plan.  Due to the $100K limitation, remaining 37,294 shares were issued and treated as a non-qualified stock option.</footnote>
<footnote id="F2">Shares granted at fair market value.</footnote>
<footnote id="F3">Incentive Stock Option granted July 14, 1999 will vest an additional 2,118 shares on July 14, 2003, increasing Mr. Stathos' available shares for exercise to 7,132 shares.  These shares have not yet been acquired through the exercise of the option.</footnote>
<footnote id="F4">Incentive Stock Option granted July 14, 1999 vests 20% per year on the anniversary date of the grant for five (5) years at which time the option becomes 100% vested.  Optionee has another five (5) years from the 100% vesting anniversary date to exercise the shares in accordance with the terms and conditions of the Company's 1996 Stock Option Plan.  No shares under this option grant have been exercised by the individual to date.</footnote>
<footnote id="F5">Additional shares becoming vested and available for exercise by Mr. Stathos at the exercise price of $17.9350 per share.</footnote>
<footnote id="F6">Non-Qualified Stock Option (right to buy).</footnote>
<footnote id="F7">Non-Qualified Stock Option granted July 14, 1999 vests 20% per year on the anniversary date of the grant for five (5) years at which time the option becomes 100% vested.  Optionee has another five (5) years from the 100% vesting anniversary date to exercise the shares in accordance with the terms and conditions of the Company's 1996 Stock Option Plan.</footnote>
</footnotes>
<ownerSignature><signatureName>James G. Stathos</signatureName>
<signatureDate>2003-07-03</signatureDate>
</ownerSignature>
</ownershipDocument>

