    <SEC-DOCUMENT>0001521951-24-000026-index.html : 20240308
    <SEC-HEADER>0001521951-24-000026.hdr.sgml : 20240308
    <ACCEPTANCE-DATETIME>20240308082401
    ACCESSION NUMBER:		0001521951-24-000026
    CONFORMED SUBMISSION TYPE:	DEFA14A
    PUBLIC DOCUMENT COUNT:		7
    FILED AS OF DATE:		20240308
    DATE AS OF CHANGE:		20240308

    FILER:

    	COMPANY DATA:
    		COMPANY CONFORMED NAME:			FIRST BUSINESS FINANCIAL SERVICES, INC.
    		CENTRAL INDEX KEY:			0001521951
    		STANDARD INDUSTRIAL CLASSIFICATION:	STATE COMMERCIAL BANKS [6022]
    		ORGANIZATION NAME:           	02 Finance
    		IRS NUMBER:				391576570
    		STATE OF INCORPORATION:			WI
    		FISCAL YEAR END:			1231

    	FILING VALUES:
    		FORM TYPE:		DEFA14A
    		SEC ACT:		1934 Act
    		SEC FILE NUMBER:	001-34095
    		FILM NUMBER:		24732420

    	BUSINESS ADDRESS:
    		STREET 1:		401 CHARMANY DRIVE
    		CITY:			MADISON
    		STATE:			WI
    		ZIP:			53719
    		BUSINESS PHONE:		608-238-8008

    	MAIL ADDRESS:
    		STREET 1:		401 CHARMANY DRIVE
    		STREET 2:		PO BOX 44961
    		CITY:			MADISON
    		STATE:			WI
    		ZIP:			53744

    	FORMER COMPANY:
    		FORMER CONFORMED NAME:	First Business Financial Services, Inc.
    		DATE OF NAME CHANGE:	20110527
    </SEC-HEADER>
    <DOCUMENT>
    <TYPE>DEFA14A
    <SEQUENCE>1
    <FILENAME>a030824defa14anoticeandbro.htm
    <DESCRIPTION>DEFA14A
    <TEXT>
    Document 1 - file: a030824defa14anoticeandbro.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>2
    <FILENAME>a03xtjb_firstxbusinessxnot.jpg
    <TEXT>
    Document 2 - file: a03xtjb_firstxbusinessxnot.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>3
    <FILENAME>a03xtjb_firstxbusinessxnota.jpg
    <TEXT>
    Document 3 - file: a03xtjb_firstxbusinessxnota.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>4
    <FILENAME>broker_pagex1.jpg
    <TEXT>
    Document 4 - file: broker_pagex1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>5
    <FILENAME>broker_pagex2.jpg
    <TEXT>
    Document 5 - file: broker_pagex2.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>6
    <FILENAME>streetcard_1.jpg
    <TEXT>
    Document 6 - file: streetcard_1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>7
    <FILENAME>streetcard_2.jpg
    <TEXT>
    Document 7 - file: streetcard_2.jpg

    </DOCUMENT>
    </SEC-DOCUMENT>