<SEC-DOCUMENT>0000357173-18-000048-index.html : 20180731
<SEC-HEADER>0000357173-18-000048.hdr.sgml : 20180731
<ACCEPTANCE-DATETIME>20180731133643
ACCESSION NUMBER:		0000357173-18-000048
CONFORMED SUBMISSION TYPE:	8-K
PUBLIC DOCUMENT COUNT:		4
CONFORMED PERIOD OF REPORT:	20180731
ITEM INFORMATION:		Regulation FD Disclosure
ITEM INFORMATION:		Financial Statements and Exhibits
FILED AS OF DATE:		20180731
DATE AS OF CHANGE:		20180731

FILER:

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			OLD SECOND BANCORP INC
		CENTRAL INDEX KEY:			0000357173
		STANDARD INDUSTRIAL CLASSIFICATION:	STATE COMMERCIAL BANKS [6022]
		IRS NUMBER:				363143493
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1215

	FILING VALUES:
		FORM TYPE:		8-K
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-10537
		FILM NUMBER:		18980540

	BUSINESS ADDRESS:	
		STREET 1:		37 S RIVER ST
		CITY:			AURORA
		STATE:			IL
		ZIP:			60507
		BUSINESS PHONE:		6308920202

	MAIL ADDRESS:	
		STREET 1:		37 SOUTH RIVER STREET
		CITY:			AURORA
		STATE:			IL
		ZIP:			60507
</SEC-HEADER>
<DOCUMENT>
<TYPE>8-K
<SEQUENCE>1
<FILENAME>osbc-20180731x8k.htm
<DESCRIPTION>8-K
<TEXT>
Document 1 - file: osbc-20180731x8k.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-99.1
<SEQUENCE>2
<FILENAME>osbc-20180731ex991f5a464.htm
<DESCRIPTION>EX-99.1
<TEXT>
Document 2 - file: osbc-20180731ex991f5a464.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>3
<FILENAME>osbc20180731ex991f5a464001.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 3 - file: osbc20180731ex991f5a464001.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>4
<FILENAME>osbc20180731x8k001.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 4 - file: osbc20180731x8k001.jpg

</DOCUMENT>
</SEC-DOCUMENT>