Incorporated Under the Laws of the State of Iowa

Exhibit 4.1

Incorporated Under the Laws of the

State of Iowa

Please See Transfer Restrictions on Reverse Side

This Certifies that the United States Department of the Treasury is the owner of Sixteen Thousand (16,000) fully paid and non-assessable shares of the Fixed Rate Cumulative Perpetual Preferred Stock, Series A, no par value, of

MIDWESTONE FINANCIAL GROUP, INC.

transferable only on the books of the Company by the holder hereof in person, or by duly authorized Attorney, upon surrender of this Certificate properly endorsed.

Any shareholder may obtain from the principal office of the Company, upon request and without charge, a statement of the number of shares constituting each class or series of stock and the designation thereof, and a copy of all the powers, designations, preferences and relative, participating, optional or other special rights of each class of stock or series thereof and the qualifications, limitations or restrictions of such preferences and/or rights and the bylaws.

IN WITNESS WHEREOF, the said Company has caused this Certificate to be signed by its duly authorized officers and its Corporate Seal hereunto affixed this 6th day of February, 2009.

THE SECURITIES REPRESENTED BY THIS INSTRUMENT ARE NOT SAVINGS ACCOUNTS, DEPOSITS OR OTHER OBLIGATIONS OF A BANK AND ARE NOT INSURED BY THE FEDERAL DEPOSIT INSURANCE CORPORATION OR ANY OTHER GOVERNMENTAL AGENCY.

THE SECURITIES REPRESENTED BY THIS INSTRUMENT HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), OR THE SECURITIES LAWS OF ANY STATE AND MAY NOT BE TRANSFERRED, SOLD OR OTHERWISE DISPOSED OF EXCEPT WHILE A REGISTRATION STATEMENT RELATING THERETO IS IN EFFECT UNDER SUCH ACT AND APPLICABLE STATE SECURITIES LAWS OR PURSUANT TO AN EXEMPTION FROM REGISTRATION UNDER SUCH ACT OR SUCH LAWS. EACH PURCHASER OF THE SECURITIES REPRESENTED BY THIS INSTRUMENT IS NOTIFIED THAT THE SELLER MAY BE RELYING ON THE EXEMPTION FROM SECTION 5 OF THE SECURITIES ACT PROVIDED BY RULE 144A THEREUNDER. ANY TRANSFEREE OF THE SECURITIES REPRESENTED BY THIS INSTRUMENT BY ITS ACCEPTANCE HEREOF (1) REPRESENTS THAT IT IS A “QUALIFIED INSTITUTIONAL BUYER” (AS DEFINED IN RULE 144A UNDER THE SECURITIES ACT), (2) AGREES THAT IT WILL NOT OFFER, SELL OR OTHERWISE TRANSFER THE SECURITIES REPRESENTED BY THIS INSTRUMENT EXCEPT (A) PURSUANT TO A REGISTRATION STATEMENT WHICH IS THEN EFFECTIVE UNDER THE SECURITIES ACT, (B) FOR SO LONG AS THE SECURITIES REPRESENTED BY THIS INSTRUMENT ARE ELIGIBLE FOR RESALE PURSUANT TO RULE 144A, TO A PERSON IT REASONABLY BELIEVES IS A “QUALIFIED INSTITUTIONAL BUYER” AS DEFINED IN RULE 144A UNDER THE SECURITIES ACT THAT PURCHASES FOR ITS OWN ACCOUNT OR FOR THE ACCOUNT OF A QUALIFIED INSTITUTIONAL BUYER TO WHOM NOTICE IS GIVEN THAT THE TRANSFER IS BEING MADE IN RELIANCE ON RULE 144A, (C) TO THE ISSUER OR (D) PURSUANT TO ANY OTHER AVAILABLE EXEMPTION FROM THE REGISTRATION REQUIREMENTS OF THE SECURITIES ACT AND (3) AGREES THAT IT WILL GIVE TO EACH PERSON TO WHOM THE SECURITIES REPRESENTED BY THIS INSTRUMENT ARE TRANSFERRED A NOTICE SUBSTANTIALLY TO THE EFFECT OF THIS LEGEND.