<SEC-DOCUMENT>0001209191-23-028889.txt : 20230512
<SEC-HEADER>0001209191-23-028889.hdr.sgml : 20230512
<ACCEPTANCE-DATETIME>20230512090034
ACCESSION NUMBER:		0001209191-23-028889
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20230113
FILED AS OF DATE:		20230512
DATE AS OF CHANGE:		20230512

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Moore Charles O
		CENTRAL INDEX KEY:			0001543854

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-36613
		FILM NUMBER:		23913456

	MAIL ADDRESS:	
		STREET 1:		110 RIVERBEND AVE
		CITY:			LEWIS CENTER
		STATE:			OH
		ZIP:			43035

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MIDDLEFIELD BANC CORP
		CENTRAL INDEX KEY:			0000836147
		STANDARD INDUSTRIAL CLASSIFICATION:	STATE COMMERCIAL BANKS [6022]
		IRS NUMBER:				341585111
		STATE OF INCORPORATION:			OH
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		15985 E HIGH ST
		STREET 2:		P O BOX 35
		CITY:			MIDDLEFILED
		STATE:			OH
		ZIP:			44062-9263
		BUSINESS PHONE:		4406321666

	MAIL ADDRESS:	
		STREET 1:		15985 EAST HIGH STREET
		STREET 2:		P O BOX 35
		CITY:			MIDDLEFIELD
		STATE:			OH
		ZIP:			44062-9263
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc4.xml
<DESCRIPTION>FORM 4 SUBMISSION
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0407</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2023-01-13</periodOfReport>

    <notSubjectToSection16>1</notSubjectToSection16>

    <issuer>
        <issuerCik>0000836147</issuerCik>
        <issuerName>MIDDLEFIELD BANC CORP</issuerName>
        <issuerTradingSymbol>MBCN</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001543854</rptOwnerCik>
            <rptOwnerName>Moore Charles O</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>15985 EAST HIGH STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>MIDDLEFIELD</rptOwnerCity>
            <rptOwnerState>OH</rptOwnerState>
            <rptOwnerZipCode>44062</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President, Central Ohio Region</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>6055.097</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Includes shares acquired under MBCN Dividend Reinvestment Plan.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Charles O. Moore by James R. Heslop, II Power of Attorney</signatureName>
        <signatureDate>2023-05-12</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
