MID PENN BANCORP INC

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a)

of the Securities Exchange Act of 1934

(Amendment No. )

Filed by the Registrant ☒

Filed by a Party other than the Registrant ☐

Check the appropriate box:

MID PENN BANCORP, INC.

(Name of Registrant as Specified In Its Charter)

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

Payment of Filing Fee (Check all boxes that apply):

March 27, 2026

Dear Shareholders:

You are cordially invited to attend the live webcast of the 2026 Annual Meeting of Shareholders of Mid Penn Bancorp, Inc. (the “Corporation”), which will be held in a virtual meeting format on Tuesday, May 12, 2026, at 10 a.m. EDT. The meeting will be conducted solely online via live webcast to enhance shareholder access by enabling attendance and participation from any location. There is no physical location for the annual meeting. In order to attend the annual meeting, you must register atwww.proxydocs.com/MPB by 12 p.m. EDT on May 11, 2026. Upon completion of your registration, you will receive further instructions via email that will provide you access to the annual meeting.

In accordance with SEC guidelines and in an effort to minimize printing, we are making the proxy materials for the Annual Meeting of Shareholders available via the Internet. The Notice of Internet Availability of Proxy Materials (“Notice”), which contains instructions on how to access the notice of annual meeting, proxy statement, and annual report on the Internet and how to execute your proxy, is first being mailed to holders of our common stock on or about March 27, 2026. This Notice also contains instructions on how to request a paper copy of the proxy materials.

The proxy statement addresses the formal business of the meeting. The formal business agenda includes the election of five Class A Directors, a non-binding vote to approve our executive compensation, and a proposal to ratify the appointment of our independent registered public accounting firm. At the meeting, management will review the Corporation’s operations during the past year. A copy of the Corporation’s annual report for the year ended December 31, 2025, is available with the proxy materials.

Your vote is very important. Whether or not you plan to attend the meeting, please vote in accordance with the instructions provided in the Notice. If you receive paper copies of the proxy materials, you may execute and return the accompanying proxy card as soon as possible in the postage-paid envelope or submit your proxy by telephone or the Internet. We encourage you to vote in advance to ensure that your shares are represented and voted at the annual meeting.

Sincerely, Rory G. Ritrievi Chair, President, and Chief Executive Officer

NOTICE OF ANNUAL MEETING OF SHAREHOLDERS

TO BE HELD MAY 12, 2026

To the Shareholders of Mid Penn Bancorp, Inc.:

Notice is hereby given that the Annual Meeting of Shareholders of Mid Penn Bancorp, Inc. (the “Corporation”) will be held on Tuesday, May 12, 2026, at 10 a.m. EDT. The meeting will be held in a virtual meeting format via a live webcast. You will not be able to attend the annual meeting in person; however, you are invited to attend the annual meeting and vote your shares via live webcast.

In order to attend the annual meeting, you must register atwww.proxydocs.com/MPB by 12 p.m. EDT on May 11, 2026. As part of the attendance process, you will be asked to provide the control number located on your Notice of Internet Availability of Proxy Materials (“Notice”), proxy card, or voting instruction form. Upon completion of your registration, you will receive further instructions via email that will provide you access to the annual meeting.

At the meeting, you will be asked to consider and act upon the following matters:

The Notice, which contains instructions on how to access the notice of annual meeting, proxy statement, and annual report on the Internet and how to execute your proxy, is first being mailed to holders of our common stock on or about March 27, 2026. This Notice also contains instructions on how to request a paper copy of the proxy materials.

In accordance with the Corporation’s Bylaws and action of the Board of Directors, only those shareholders of record at the close of business on March 13, 2026, are entitled to notice of, and to vote at, the annual meeting and any adjournment or postponement thereof.

If you accessed this proxy statement through the Internet after receiving a Notice, you may cast your vote by telephone or over the Internet by following the instructions on that Notice. If you received this proxy statement by mail, you may cast your vote by mail, by telephone, or over the Internet by following the instructions on the accompanying proxy card.

Whether or not you plan to attend the virtual annual meeting, your vote is very important, and we encourage you to vote promptly. You may vote your shares in advance of the meeting via the Internet, by telephone or by mail, or by attending and voting online at the 2026 Annual Meeting of Shareholders. Please refer to the section “How to Vote” on page i for detailed voting instructions.

If you execute a proxy but later decide to attend the annual meeting virtually, or for any other reason desire to revoke your proxy, you may do so as described in this proxy statement at any time before your proxy is voted. Submitting a proxy will not prevent you from attending the annual meeting virtually and voting electronically during the meeting if you so desire, but it will help us secure a quorum and reduce the expense of additional proxy solicitation.

By Order of the Board of Directors,

Rory G. Ritrievi

Board Chair

IMPORTANT NOTICE REGARDING THE AVAILABILITY OF PROXY MATERIALS FOR THE SHAREHOLDER MEETING TO BE HELD ON MAY 12, 2026: The proxy statement, proxy card and 2025 annual report to shareholders are available atwww.proxydocs.com/MPB.

2407 Park Drive, Harrisburg, Pennsylvania 17110

PROXY STATEMENT

2026 ANNUAL MEETING OF SHAREHOLDERS

MAY 12, 2026

Nasdaq Global Market Trading Symbol: MPB

This proxy statement is furnished by the Board of Directors of Mid Penn Bancorp, Inc. and

is being first provided to shareholders on or about March 27, 2026.