​

I

​

United States

Securities And Exchange Commission
Washington, D.C. 20549

​

FORM 8-K

​

Current Report

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): May 19, 2026

(Exact name of registrant as specified in its charter)

​

37 South River Street
Aurora, Illinois 60507
(Address of principal executive offices) (Zip code)

(630) 892-0202
(Registrant’s telephone number, including area code)

N/A

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

☐   Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐   Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐   Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐   Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

​

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 under the Securities Act (17 CFR 230.405) or Rule 12b-2 under the Exchange Act (17 CFR 240.12b-2).

Emerging growth company  ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.  ☐

​

​

​

​

Item 5.07. Submission of Matters to a Vote of Security Holders

​

On May 19, 2026, Old Second Bancorp, Inc. (the “Company”) held its Annual Meeting of Stockholders (the “Annual Meeting”). Of the 51,779,472 shares of common stock eligible to vote at the Annual Meeting, 44,215,472 shares were represented in person or by proxy, representing approximately 85.39% of the outstanding shares. At the Annual Meeting, the stockholders elected Darin Campbell, Billy J. Lyons, Jr., Patti Temple Rocks, and John Williams, Jr. as Class I directors to serve a term expiring in 2029, and voted on the two additional proposals listed below. Further detail on each of the matters voted on by the stockholders is available in the Company’s Definitive Proxy Statement.

​

The final results of voting on each of the matters submitted to a vote of common stockholders during the Annual Meeting are as follows:

​

​

​

​

​

​

​

​

​

Signature

Pursuant to the requirements of the Securities Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

​

​

​

​