UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON,Washington, D.C. 20549

SCHEDULE 14A INFORMATION

Proxy Statement Pursuant to Section 14(a) of the Securities

Securities Exchange Act of 1934 (Amendment No. )

(Amendment No.)

Filed by the Registrant  ☒                             Filed by a Party other than the Registrant  ☐

Check the appropriate box:

Riverview Financial Corporation

(Name of Registrant as Specified In Its Charter)

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

Payment of Filing Fee (Check the appropriate box):

Prospectus

Joint Proxy Statement/Prospectus

MERGER PROPOSED—YOUR VOTE IS VERY IMPORTANT

Dear Shareholder:

On June 30, 2021, Mid Penn Bancorp, Inc., or Mid Penn, and Riverview Financial Corporation, or Riverview, entered into a merger agreement, as amended on August 26, 2021, under which Riverview will merge with and into Mid Penn, with Mid Penn remaining as the surviving entity. Before we complete the merger, the shareholders of Mid Penn and Riverview must approve and adopt the merger agreement.

Mid Penn shareholders will vote to adopt the merger agreement and on the other matters described below at a special meeting of shareholders to be held virtually via live webcast at https://meetnow.global/MQZ7KWP at 10:00 a.m., Eastern Time, on November 18, 2021. Riverview shareholders will vote to adopt the merger agreement and on the other matters described below at a special meeting of shareholders to be held virtually via the internet at www.virtualshareholdermeeting.com/RIVE2021SM at 10:00 a.m., Eastern Time, on November 18, 2021. Information regarding how Mid Penn shareholders and Riverview shareholders can attend and participate in their respective special meetings of shareholders is included in the proxy card for the respective companies included with this joint proxy statement/prospectus.

If the merger is completed, Riverview shareholders will have the right to receive for each share of Riverview common stock they own 0.4833 shares of Mid Penn common stock. Cash will be paid in lieu of any fractional shares. The maximum number of shares of Mid Penn common stock estimated to be issuable upon completion of the merger is 4,524,639. Following the completion of the merger, former Riverview shareholders will hold approximately 28.2% of Mid Penn’s common stock.

The common stock of Mid Penn trades on the Nasdaq Global Select Market under the symbol “MPB” and the common stock of Riverview trades on the Nasdaq Global Select Market under the symbol “RIVE.” On June 29, 2021, which was the last trading date preceding the public announcement of the proposed merger, the closing price of Mid Penn common stock and Riverview common stock was $27.47 per share and $11.90 per share, respectively. On October 5, 2021, the most recent practicable trading day prior to the printing of this joint proxy statement/prospectus, the closing price of Mid Penn common stock and Riverview common stock was $27.89 per share and $13.28 per share, respectively. The market price of both Mid Penn common stock and Riverview common stock will fluctuate before the completion of the merger; therefore, you are urged to obtain current market quotations for Mid Penn common stock and Riverview common stock. Additionally, as described in more detail elsewhere in this joint proxy statement/prospectus, under the terms of the merger agreement, if the average price of Mid Penn common stock over a specified period of time decreases below certain specified thresholds, Riverview would have a right to terminate the merger agreement, unless Mid Penn elects to increase the exchange ratio, which would result in additional shares of Mid Penn common stock being issued.

The Mid Penn board of directors has determined that the merger is advisable and in the best interests of Mid Penn and the Mid Penn board of directors unanimously recommends that the Mid Penn shareholders vote “FOR” the adoption of the merger agreement and “FOR” the approval of the other proposals described in this joint proxy statement/prospectus.

The Riverview board of directors has determined that the merger is advisable and in the best interests of Riverview and the Riverview board of directors unanimously recommends that the Riverview shareholders vote “FOR” the adoption of the merger agreement and “FOR” the approval of the other proposals described in this joint proxy statement/prospectus.

Your vote is very important. Whether or not you plan to attend your shareholders’ meeting, please take the time to vote by completing and mailing the enclosed proxy card in accordance with the instructions on the proxy card. Mid Penn and Riverview shareholders may also cast their votes over the Internet or by telephone in accordance with the instructions on the Mid Penn or Riverview proxy card or voting instructions, as the case may be. We cannot complete the merger unless Mid Penn and Riverview shareholders approve and adopt the merger agreement.

You should read this entire joint proxy statement/prospectus, including the annexes hereto and the documents incorporated by reference herein, carefully because it contains important information about the merger and the related transactions. In particular, you should read carefully the information under the section entitled “Risk Factors” beginning on page 32. You can also obtain information about Mid Penn and Riverview from documents that each has filed with the Securities and Exchange Commission.

We strongly support this combination of our companies and join with the other members of our boards of directors in enthusiastically recommending that you vote in favor of the merger.

Rory G. Ritrievi		Brett D. Fulk
President and Chief Executive Officer		President and Chief Executive Officer
Mid Penn Bancorp, Inc.		Riverview Financial Corporation

The shares of Mid Penn common stock to be issued to Riverview shareholders in the merger are not deposits or savings accounts or other obligations of any bank or savings association, and are not insured by the Federal Deposit Insurance Corporation or any other governmental agency.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved the Mid Penn common stock to be issued in the merger, or passed upon the adequacy or accuracy of this joint proxy statement/prospectus. Any representation to the contrary is a criminal offense.

The date of this joint proxy statement/prospectus is October 5, 2021, and it is first being mailed or otherwise delivered to Mid Penn shareholders and Riverview shareholders on or about October 12, 2021.

This document incorporates important business and financial information about Mid Penn and Riverview that is not included in or delivered with this document. This information is available without charge to shareholders upon written or oral request at either Mid Penn’s or Riverview’s address and telephone number listed on page i. To obtain timely delivery, Mid Penn shareholders must request the information no later than November 4, 2021 and Riverview shareholders must request this information no later than November 4, 2021. Please see “Where You Can Find More Information” on page 117 for instructions to request this and certain other information regarding Mid Penn and Riverview.

RIVERVIEW FINANCIAL CORPORATION

3901 NORTH FRONT STREET

HARRISBURG, PENNSYLVANIA 17110

(717)957-2196

NOTICE OF ANNUALSPECIAL MEETING OF SHAREHOLDERS

TO BE HELD ON JUNE 13, 2019THURSDAY, NOVEMBER 18, 2021

TO THE SHAREHOLDERS OF RIVERVIEW FINANCIAL CORPORATION:

NOTICE IS HEREBY GIVEN that the Annual Meetinga special meeting of the Shareholdersshareholders of Riverview Financial Corporation, (the “Corporation”)or Riverview, will be held virtually via the internet at the Toftrees Golf Resort and Conference Center, One Country Club Lane, State College, Pennsylvania, 16803, on Thursday, June 13, 2019www.virtualshareholdermeeting.com/RIVE2021SM at 10:00 a.m., local time, for the purpose of consideringEastern Time, on November 18, 2021, to consider and voting upon the following matters:vote on:

The BoardYou are entitled to dissent from the merger and receive payment for the fair value of Directors recommends that you vote “FOR”your shares under 15 Pa.C.S. §1571. Any shareholder who wishes to exercise these rights must strictly comply with the election of each of the nominees for directors listedprocedures described in the attached joint proxy statement; “FOR” approvalstatement/prospectus, which are also attached as Annex D to this joint proxy statement/prospectus.

These items are described in more detail in the accompanying joint proxy statement/prospectus and adoption of the Riverview Financial Corporation 2019 Equity Incentive Plan; and “FOR” the ratification of the appointment of Crowe LLPits annexes. You should read these documents in their entirety before voting. We have fixed September 30, 2021 as the independent registered public accounting firmrecord date for determining those Riverview shareholders entitled to vote at the fiscal year ending December 31, 2019.

Only thosespecial meeting. Accordingly, only shareholders of record, at the close of business on April 15, 2019,that date are entitled to receive notice of and to vote at the special meeting or any adjournment or postponement of the meeting. See the “Questions & Answers” section of the accompanying joint proxy statement/prospectus for more information, including technical support information for Riverview’s virtual special meeting.

Your board of directors has unanimously determined that the proposed merger is advisable and in the best interests of Riverview encouragesand unanimously recommends that you vote “FOR” the Riverview merger proposal, “FOR” the Riverview compensation proposal and “FOR” the Riverview adjournment proposal. In accordance with the terms of the merger agreement, each director, executive officer and ten percent (10%) shareholder of Riverview has agreed to vote all shares of Riverview common stock owned by him, her or it, that he, she or it, directly or indirectly, controls the right to vote and dispose of, in favor of approval and adoption of the merger agreement and the transactions contemplated thereby.

We urge you to vote your shares in advance of the Annual Meetingas soon as possible so that your shares will be represented and votedrepresented.

Your vote is very important, regardless of the number of shares of Riverview common stock that you own. Assuming a quorum is present, we cannot complete the merger unless the affirmative vote of at least a majority of the votes cast at the Annual Meetingspecial meeting votes to approve and adopt the Riverview merger proposal.

Even if you cannotplan to virtually attend the special meeting (information regarding how you can attend and participate in personthe special meeting is included in the proxy card), Riverview requests that you complete, sign, date and are eligible to vote.You may vote by signing and returningreturn, as promptly as possible, the enclosed proxy card in the accompanying prepaid reply envelope or submit your proxy card by mail inInternet prior to the enclosed postpaid envelope, by telephone, viaspecial meeting to ensure that your shares of Riverview common stock will be represented at the internet or by attending the meeting and votingspecial meeting. If you hold your shares in person.For telephone voting, call toll-free,1-800-776-9437 from any touch-tone telephone and“street name” through a bank, brokerage firm or other nominee, you should follow the instructions. For internet voting, accesswww.voteproxy.com and follow theon-screen instructions. Whether votingprocedures provided by telephoneyour bank, brokerage firm or via internet, ensure thatother nominee to vote your shares. If you have yourfail to submit a proxy card available.

We cordially invite youor to virtually attend the meeting. Your proxy is revocable. You may revokespecial meeting and vote or do not provide your proxy at any time priorbank, brokerage firm or other nominee with instructions as to thehow to vote by submitting a later-dated proxy using one of the methods referred to above or by delivering written notice of revocation to the secretary at the Annual Meeting. Shareholders may voteyour shares, as often as they wish via telephone or internet, but only the last vote received will be tabulated. Telephone and internet sites are closed at 11:59 p.m., Eastern Time, on the day prior to the meeting.

Enclosed is a copyapplicable, your shares of Riverview Financial Corporation’s annual report on Form10-K for the fiscal year ended December 31, 2018.common stock will not be counted.

BY THE ORDER OF THE BOARD OF DIRECTORS,

Kathy Ann Paul

SecretaryMelinda Aungst

3901 North Front StreetCorporate Secretary

Harrisburg, Pennsylvania

May 1, 2019October 5, 2021

RIVERVIEW SHAREHOLDERS SHOULD NOT SEND STOCK CERTIFICATES AT THIS TIME. YOU WILL BE SENT SEPARATE INSTRUCTIONS ABOUT HOW TO RECEIVE THE MERGER CONSIDERATION AND THE SURRENDER OF YOUR STOCK CERTIFICATES.

Important Notice RegardingHOW TO OBTAIN ADDITIONAL INFORMATION

This joint proxy statement/prospectus incorporates by reference important business and financial information about Mid Penn and Riverview that is not included in or delivered with this document. You can obtain free copies of this information through the Availability of Proxy Materials

for the Annual Meeting to be Held on June 13, 2019:

Our Proxy Statement on Schedule 14A, form of proxy card and 2018 Annual Report on Form10-K are available at:SEC website at https://riverviewbankpa.com/www.sec.gov. You will also be able to obtain these documents, free of charge, from Mid Penn at www.midpennbank.com, under the heading “SEC Filings” or from Riverview by clicking onaccessing Riverview’s website at www.riverviewbankpa.com, under theInvestor Relations link.

PROXY STATEMENT

Date, Timerefer to as the “Securities Act,” with respect to the shares of common stock, par value $1.00 per share, of Mid Penn, which we refer to as “Mid Penn common stock,” to be issued pursuant to the Agreement and PlacePlan of Annual Meeting

The Annual MeetingMerger, dated as of June 30, 2021, by and between Mid Penn and Riverview, which we refer to as the shareholders“merger agreement.” This document also constitutes a proxy statement of Mid Penn and Riverview Financial Corporation (the “Corporation”) will be held on Thursday, June 13, 2019, at 10:00 a.m. atunder the Toftrees Golf Resort and Conference Center, One Country Club Lane, State College, Pennsylvania, 16803. Only shareholders of record at the close of business on April 15, 2019 (the “Record Date”) are entitled to receiveExchange Act. It also constitutes a notice of meeting with respect to attend,the special meetings, at which each of Mid Penn and to vote at the meeting.

Proposals to be Voted on at the Annual Meeting

At the Annual Meeting,Riverview shareholders will be asked to consider and vote upon the following matters:

Solicitation of Proxies

This proxy statement is being furnished in connection with the solicitation of proxies by the Board of Directors of the Corporation for the 2019 Annual Meeting of Shareholders. This proxy statement and the related proxy card are first being distributed on or about May 1, 2019. The Corporation will bear the expense of soliciting proxies. Copies of solicitation materials will be furnished to brokerage houses, fiduciaries and custodians to forward to beneficial owners of stock held in the names of such nominees. The Corporation will reimburse brokers and other custodians, nominees and fiduciaries for their reasonableout-of-pocket expenses for forwarding proxy and solicitation materials to owners of the Corporation’s Common Stock. In addition to the solicitation of proxies by mail, directors, officers and employees of the Corporation and its subsidiaries may, without additional compensation, solicit proxies in person, by telephone, and through other means of communication.

Riverview encourages you to vote your shares by proxy, using the enclosed proxy card, or by using the telephone or internet voting options described on the proxy card in advance of the Annual Meeting so that your shares will be represented and voted at the Annual Meeting if you cannot attend in person and are eligible to vote.You may vote by signing and returning the enclosed proxy card by mail in the enclosed postpaid envelope, electronically by telephone or the internet using the instructions stated on the enclosed proxy card or by attending the Annual Meeting and voting in person. For telephone voting, call toll-free,1-800-776-9437 from any touch-tone telephone and follow the instructions. For internet voting, access www.voteproxy.com and follow theon-screen instructions. Whether voting by telephone or via internet, ensure that you have your proxy card available.

If you hold shares in street name with a bank or broker, it is important that you instruct your bank or broker how to vote your shares if you want your shares to be voted on the election of directors or on the adoption of the 2019 Equity Incentive Plan. If you hold your shares in street name and you do not instruct your bank or broker how to vote your shares in the election of directors or approval and adoption of the 2019 Equity Incentive Plan, no votes will be cast on your behalf for those matters unless you provide instructions to your broker on how to vote. Your bank or broker will, however, continue to have discretion to vote any shares for which no voting instructions have been provided on the ratification of the appointment of Riverview’s independent auditor and other matters that your bank or broker considers routine.

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PROPOSAL 1: ELECTIONTABLE OF DIRECTORS

The Corporation’s Articles of Incorporation provide that the Board of Directors shall consist of at least seven (7), but not more than twenty-five (25) persons, as determined by the Board of Directors from time to time. The Board currently has fifteen (15) members; however, effective as of the Annual Meeting, the total number of members of the Board will be reduced to fourteen (14), as described below. The Board is divided into three classes, as nearly equal in number as possible. Directors serve staggered, three-year terms, such that the term of office of one class of directors expires each year. Currently, the term of the Class 1 directors expires at the 2020 Annual Meeting, the term of Class 2 directors expires at the 2021 Annual Meeting, and the term of Class 3 directors expires at the 2019 Annual Meeting.

Any vacancy occurring on the Board of Directors, whether due to an increase in the number of directors, resignations, retirement, death or any other reason, may be filled by a majority of the remaining members of the Board of Directors, or by a sole remaining director, though less than a quorum, and each person so appointed will serve as a director until the expiration of the term of office of the class of directors to which he or she was appointed. The Bylaws do not permit the nomination of any individual as a director who shall have attained the age of seventy (70) years on or before the date of the Annual Meeting at which directors are to be elected. As of the 2019 Annual Meeting, Director Charles R. Johnston, Jr. is retiring from the Board as a result of this requirement, thus reducing the size of the Board to fourteen (14) members. The ages of the directors presented in the table are as of the April 15, 2019 Record Date.

Except for directors of the Corporation who were in office as of September 27, 2018, no person shall be nominated or elected to serve as a Director who beneficially owns less than 2,000 shares of common stock of the Corporation as of both the date they are nominated and the date they are elected to serve on the Board. A director shall beneficially own at least 4,000 shares of common stock of the Corporation by thetwo-year anniversary of the date of their election or appointment to the Board. Notwithstanding the foregoing, directors serving on the Board of the Corporation as of September 27, 2018 shall instead beneficially own at least 4,000 shares of common stock before year end 2020 to remain on the Board of the Corporation. All ownership requirements are continuous; a director must maintain the applicable level of ownership at all times until termination of their service as a member of the Board. Any member of the Board who fails to reach or maintain the required level of ownership shall be required to immediately resign from the Board as of the date such requirement is no longer met.

The Board of Directors has nominated the following four (4) persons for election as Class 3 directors, to serve for a three-year term and until their successors are duly elected and qualified. In the event that any of the nominees are unable to accept nomination or election, proxy holders will vote proxies given pursuant to this solicitation in favor of other persons recommended by the Board of Directors. The Board of Directors has no reason to believe that any of the nominees will be unable to serve as a director if elected.

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Class 2 Directors to serve until 2021

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QUESTIONS AND ANSWERS ABOUT THE MERGER AND THE SPECIAL MEETINGS

The following questions and answers briefly address some commonly asked questions about the merger (as defined below) and the shareholder meetings. They may not include all the information that is important to the shareholders of Mid Penn and Riverview. Shareholders of Mid Penn and Riverview should each read carefully this entire joint proxy statement/prospectus, including the annexes and other documents referred to in this joint proxy statement/prospectus.

Questions about the Merger

SHARE OWNERSHIP

Principal Holders

Persons and groups who beneficially own in excess of five percent of Riverview’s issued and outstanding voting shares of Common Stock are required to file certain reports with the Securities and Exchange Commission (“SEC”) regarding such beneficial ownership. The following table showsRiverview Bank will cease. We refer to this transaction as of February 28, 2019, certain information as to the parties who beneficially owned more than five percent of our Common Stock. We know of no persons, except as listed below, who beneficially owned more than five percent of our voting common stock as of February 28, 2019.

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Mid Penn is providing this joint proxy statement/prospectus to its shareholders because the Mid Penn Board of Directors is soliciting their proxy for use at the Mid Penn special meeting of shareholders at which the Mid Penn shareholders will consider and vote on (i) approval and adoption of the merger agreement which provides for, among other things, the merger of Riverview with and into Mid Penn (the “Mid Penn merger proposal”) and (ii) approval of the authorization of the board of directors to adjourn the Mid Penn special meeting, if necessary, to solicit additional proxies, in the event there are not sufficient votes at the time of the special meeting to approve the Mid Penn merger proposal (the “Mid Penn adjournment proposal”). See “The Mid Penn Special Meeting,” beginning on page 98 for more information.

Riverview is providing this joint proxy statement/prospectus to its shareholders because the Riverview Board of Directors is soliciting their proxy for use at the Riverview special meeting of shareholders at which the Riverview shareholders will consider and vote on (i) approval and adoption of the merger agreement which provides for, among other things, the merger of Riverview with and into Mid Penn (the “Riverview merger proposal”), (ii) approval, on an advisory (non-binding) basis, of the merger-related compensation payments that will or may be paid to the named executive officers of Riverview in connection with the transactions contemplated by the merger agreement (the “Riverview compensation proposal”), and (iii) approval of the authorization of the board of directors to adjourn the Riverview special meeting, if necessary, to solicit additional proxies, in the event there are not sufficient votes at the time of the special meeting to approve the Riverview merger proposal (the “Riverview adjournment proposal”). See “The Riverview Special Meeting,” beginning on page 102 for more information.

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Beneficial OwnershipInformation about these meetings, the merger and the other business to be considered at the meetings is contained in this joint proxy statement/prospectus. The merger cannot be completed unless shareholders of Executive Officers, DirectorsMid Penn and NomineesRiverview each approve the merger.

The following table shows, as of February 28, 2019,

On June 29, 2021, which was the amount and percentage of each class of equity securitieslast trading date preceding the public announcement of the Corporation’s beneficially ownedproposed merger, the closing price of Mid Penn common stock was $27.47 per share, which, after giving effect to the 0.4833 exchange ratio, would result in merger consideration with an implied value of approximately $13.27 per share of Riverview common stock. On October 5, 2021, the most recent practicable trading day prior to the printing of this joint proxy statement/prospectus, the closing price of Mid Penn common stock was $27.89 per share, which, after giving effect to the 0.4833 exchange ratio, would result in merger consideration with an implied value of approximately $13.48 per share of Riverview common stock. The market price of both Mid Penn common stock and Riverview common stock will fluctuate before the completion of the merger; therefore, you are urged to obtain current market quotations for Mid Penn common stock and Riverview common stock.

Because of the number of shares of Mid Penn common stock being issued in the merger, the percentage ownership interest in Mid Penn represented by the existing shares of Mid Penn common stock will be diluted. Mid Penn shareholders will not receive any merger consideration and will continue to own their existing shares of Mid Penn common stock after the merger.

Stock Options: At the effective time of the merger, each director,option to purchase shares of Riverview common stock outstanding immediately before the effective time of the merger, whether or not vested, will be canceled and exchanged for a cash payment equal to the product of (1) the number of shares of Riverview common stock subject to the stock option multiplied by (2) the closing sale price of Mid Penn common stock on the fifth business day prior to the closing date of the merger multiplied by 0.4833, less the per share exercise price of the Riverview option, without interest.

Restricted Stock Awards: At the effective time of the merger, each director nominee,outstanding share of restricted stock will vest and be converted into the right to receive the merger consideration.

This tax treatment may not apply to all Riverview shareholders. Determining the actual tax consequences of the merger to Riverview shareholders can be complicated. Riverview shareholders should consult their own tax advisor for a full understanding of the merger’s tax consequences that are particular to each named executive officershareholder. For further discussion of the material U.S. federal income tax consequences of the merger, see “Material United States Federal Income Tax Consequences of the Merger,” beginning on page 95.

Questions about the Mid Penn Special Meeting

As of the record date, directors nominees and executive officers of Mid Penn and their affiliates had the Corporation as a group.

Unless otherwise indicated in a footnote appearing below the table, all shares reported in the following table are owned directly by the reporting person. The number of shares owned by the directors, nominees and executive officers is roundedright to the nearest whole share. All shares reported arevote 1,620,890 shares of Common Stock, and noneMid Penn common stock, or 14.2% of the outstanding Mid Penn common stock entitled to be voted at the special meeting. Each of the directors and executive officers owns any other class of equityMid Penn have agreed to vote all shares of Mid Penn common stock owned by him or her that he or she, directly or indirectly, controls the right to vote and dispose of, in favor of adoption of the Corporation.merger agreement.

Voting by Proxy. Mid Penn shareholders of record may vote their Mid Penn shares by completing and returning the enclosed proxy card. Your proxy will be voted in accordance with your instructions. If you submit a properly executed and dated proxy, but do not specify a choice on one of the proposals described in this joint proxy statement/prospectus, your proxy will be voted in favor of that proposal.

Voting by Internet. If you are a registered shareholder, you may vote electronically through the Internet by following the instructions included on your proxy card. If your shares are registered in the name of a broker or other nominee, you may be able to vote via the Internet. If so, the voting form your nominee sends you will provide Internet instructions.

Voting by Phone. Use any touch-tone telephone to transmit your voting instructions up until 11:59 p.m. Eastern Time the day before the meeting date. Have your proxy card in hand when you call 1-800-652-8683 and then follow the instructions.

Voting Virtually at the Special Meeting. Mid Penn shareholders of record may virtually attend the Mid Penn special meeting and vote. Information regarding how to virtually attend the special meeting is included below and in the proxy card. If your shares are registered in the name of a broker or other nominee and you wish to vote at the meeting you will need to obtain a legal proxy from your bank or brokerage firm. Please consult the voting form sent to you by your bank or broker to determine how to obtain a legal proxy in order to vote at the special meeting.

You will be able to attend the special meeting online and submit your questions during the meeting by visiting https://meetnow.global/MQZ7KWP. You also will be able to vote your shares online by attending the special meeting by webcast.

To participate in the special meeting, you will need to review the information included below and on your proxy card.

If you hold your shares through an intermediary, such as a bank or broker, you must register in advance using the instructions below.

The online meeting will begin promptly at 10:00 a.m., Eastern Time. We encourage you to access the meeting prior to the start time leaving ample time for the check in. Please follow the registration instructions as outlined in this proxy statement.

If you hold your shares through an intermediary, such as a bank or broker, you must register in advance to attend the special meeting virtually on the Internet.

To register to attend the special meeting online by webcast you must submit proof of your proxy power (legal proxy) reflecting your Mid Penn holdings along with your name and email address to Computershare. Requests for registration must be labeled as “Legal Proxy.”

You will receive a confirmation of your registration by email after we receive your registration materials.

Requests for registration should be directed to us at the following:

By email

Forward the email from your broker, or attach an image of your legal proxy, to legalproxy@computershare.com

By mail

Computershare

Mid Penn Legal Proxy

P.O. Box 43001

Providence, RI 02940-3001

Any shareholder entitled to vote virtually at the special meeting may vote regardless of whether a proxy has been previously given, and such vote will revoke any previous proxy, but the mere virtual presence (without notifying Mid Penn’s Corporate Secretary) of a shareholder at the special meeting will not constitute revocation of a previously given proxy. A shareholder may change his or her vote up and until the time that votes are counted but not thereafter.

Mid Penn will bear the cost of preparing and assembling these proxy materials for the Mid Penn special meeting. The cost of printing and mailing these proxy materials will be shared equally between Mid Penn

and Riverview. The solicitation of proxies or votes for the Mid Penn special meeting may also be made in person, by telephone, or by electronic communication by Mid Penn’s directors, officers, and employees, none of whom will receive any additional compensation for such solicitation activities. In addition, Mid Penn may reimburse brokerage firms and other persons representing beneficial owners of shares for their expenses in forwarding solicitation material to such beneficial owners.

Mid Penn Bancorp, Inc.

349 Union Street

Millersburg, Pennsylvania 17061

Attention: Investor Relations

Telephone: (717) 692-7105

Questions about the Riverview Special Meeting

As of the record date, directors, executive officers and ten percent (10%) shareholders of Riverview and their affiliates had the right to vote 2,283,902 shares of Riverview common stock, or approximately 24.4% of the outstanding Riverview common stock entitled to be voted at the Riverview special meeting. Each of the directors, executive officers and ten percent (10%) shareholders of Riverview have agreed to vote all shares of Riverview common stock owned by him, her or it that he, she or it, directly or indirectly, controls the right to vote and dispose of, in favor of adoption of the merger agreement.

Voting by Proxy. You may vote your Riverview shares by completing and returning the enclosed proxy card. Your proxy will be voted in accordance with your instructions. If you submit a properly executed and dated proxy, but do not specify a choice on one of the proposals described in this joint proxy statement/prospectus, your proxy will be voted in favor of that proposal.

Voting by Internet. If you are a registered shareholder, you may vote electronically through the Internet by following the instructions included on your proxy card. If your shares are registered in the name of a broker or other nominee, you may be able to vote via the Internet. If so, the voting form your nominee sends you will provide Internet instructions.

Voting by Phone. Use any touch-tone telephone to transmit your voting instructions up until 11:59 p.m. Eastern Time the day before the meeting date. Have your proxy card in hand when you call 1-800-690-6903 and then follow the instructions.

Voting Virtually at the Special Meeting. You may virtually attend the Riverview special meeting and vote. Information regarding how to virtually attend the special meeting is included in the proxy card. See the question “Can I attend the Riverview special meeting and vote my shares virtually?” below for more information on how to vote at the virtual special meeting.

Riverview encourages its shareholders to visit the meeting website above in advance of the Riverview special meeting to familiarize themselves with the online access process. The virtual Riverview special meeting platform is fully supported across browsers and devices that are equipped with the most updated version of applicable software and plugins. Shareholders should verify their internet connection prior to the Riverview special meeting. If you have difficulty accessing the virtual Riverview special meeting during check-in or during the meeting, please contact technical support as indicated on the Riverview special meeting sign-in page. Shareholders will have substantially the same opportunities to participate in the virtual Riverview special meeting as they would have at a physical, in-person meeting. Shareholders as of the record date will be able to attend, vote, and submit questions during a portion of the meeting via the online platform.

Even if you plan to attend the Riverview special meeting virtually, Riverview recommends that you vote your shares in advance so that your vote will be counted if you later decide not to or become unable to attend the Riverview special meeting.

Additional information on attending the Riverview virtual special meeting can be found under the section entitled “The Riverview Special Meeting—Attending the Virtual Special Meeting” on page 103.

Any shareholder entitled to vote virtually at the special meeting may vote regardless of whether a proxy has been previously given, and such vote will revoke any previous proxy, but the mere virtual presence (without notifying Riverview’s Corporate Secretary) of a shareholder at the special meeting will not constitute revocation of a previously given proxy. A shareholder may change his or her vote up and until the time that votes are counted but not thereafter.

Riverview will bear the cost of preparing and assembling these proxy materials for the Riverview special meeting. The cost of printing and mailing these proxy materials will be shared equally between Mid Penn and Riverview. The solicitation of proxies or votes for the Riverview special meeting may also be made in person, by telephone, or by electronic communication by Riverview’s directors, officers, and employees, none of whom will receive any additional compensation for such solicitation activities. In addition, Riverview may reimburse brokerage firms and other persons representing beneficial owners of shares for their expenses in forwarding solicitation material to such beneficial owners.

Riverview Financial Corporation

3901 North Front Street

Harrisburg, Pennsylvania 17110

Attention: Corporate Secretary

Telephone: (717) 957-2196

SUMMARY

This summary highlights information contained elsewhere in this joint proxy statement/prospectus and may not contain all of the information that is important to you. We urge you to carefully read the entire joint proxy statement/prospectus and the other documents to which we refer in order to fully understand the merger and the related transactions. See “Where You Can Find More Information.”

Information about the Parties

Mid Penn Bancorp, Inc.

Formed in 1991, Mid Penn Bancorp, Inc. is the financial holding company for Mid Penn Bank, a full-service Pennsylvania chartered bank and trust company originally organized in 1868, as well as three nonbank subsidiaries formed in 2020 to further expand its suite of products and services. Mid Penn is regulated by the Board of Governors of the Federal Reserve System.

Headquartered in Millersburg, Pennsylvania, Mid Penn Bank services its customers and communities through thirty-six retail banking locations located in the Pennsylvania counties of Berks, Bucks, Chester, Cumberland, Dauphin, Fayette, Lancaster, Luzerne, Montgomery, Northumberland, Schuylkill and Westmoreland. Mid Penn Bank engages in full-service commercial banking and trust business, making available to the community a wide range of financial services, including, but not limited to, mortgage and home equity loans, secured and unsecured commercial and consumer loans, lines of credit, construction financing, farm loans, community development and local government loans and various types of time and demand deposits. In addition, Mid Penn Bank provides a full range of trust and retail investment services, as well as online banking, telephone banking, cash management services, automated teller services and safe deposit boxes. Mid Penn Bank is regulated by the Pennsylvania Department of Banking and Securities Authorized for Issuance Under Equity Compensation Plansand the Federal Deposit Insurance Corporation.

The following table disclosesprincipal executive offices of Mid Penn are located at 349 Union Street, Millersburg, Pennsylvania 17061 and its telephone number is (717) 692-2133.

Mid Penn common stock is traded on The Nasdaq Global Select Market under the numbersymbol “MPB.”

Riverview Financial Corporation

Riverview was formed in 2013 as a bank holding company incorporated under the laws of outstanding options grantedPennsylvania. Riverview is regulated by the Board of Governors of the Federal Reserve System. Riverview provides a full range of financial services through its wholly-owned bank subsidiary, Riverview Bank, which is its sole operating segment.

Riverview Bank is a state-chartered bank and trust company regulated by the Pennsylvania Department of Banking and Securities and the Federal Deposit Insurance Corporation that offers financial services through 27 community banking offices and three limited purpose offices. The Wealth and Trust Management divisions of Riverview Bank provide trust and investment advisory services to participantsthe general public and businesses. Riverview Bank’s market area consists of Berks, Blair, Bucks, Centre, Clearfield, Cumberland, Dauphin, Huntingdon, Lebanon, Lehigh, Lycoming, Perry, Schuylkill and Somerset Counties in Central Pennsylvania.

The principal executive offices of Riverview are located at 3901 North Front Street, Harrisburg, Pennsylvania 17110, and its telephone number is (717) 957-2196.

Riverview common stock is traded on the Nasdaq Global Select Market under the symbol “RIVE.”

The Merger and the Merger Agreement (pages 41 and 82)

The terms and conditions of the merger are contained in the merger agreement, which is attached as Annex A to this joint proxy statement/prospectus and incorporated by reference herein. Please carefully read the merger agreement as it is the legal document that governs the merger.

Pursuant to the merger agreement, Riverview will merge with and into Mid Penn with Mid Penn as the surviving corporation. Immediately after the merger, Riverview Bank will merge with and into Mid Penn Bank, with Mid Penn Bank as the surviving bank.

Mid Penn Will Hold Its Special Meeting on Thursday, November 18, 2021 (page 98)

The Mid Penn special meeting will be held virtually via live webcast at https://meetnow.global/MQZ7KWP on November 18, 2021 at 10:00 a.m., Eastern Time. At the special meeting, Mid Penn shareholders will be asked to:

Record Date. Only holders of record of Mid Penn common stock at the close of business on September 30, 2021 will be entitled to vote at the special meeting. Each share of Mid Penn common stock is entitled to one vote. As of the Mid Penn record date, there were 11,532,007 shares of Mid Penn common stock issued and 11,433,555 shares were outstanding and entitled to vote at the special meeting.

Required Vote. The affirmative vote, in person or by proxy, of at least sixty-six and two thirds percent (66 2/3%) of the outstanding shares of Mid Penn common stock is required to approve the Mid Penn merger agreement, and a majority of the votes cast at the special meeting is required to approve the Mid Penn adjournment proposal. The presence, in person or by proxy, of a majority of the outstanding shares of Mid Penn common stock is necessary to constitute a quorum in order to transact business at the special meeting.

As of the record date, directors and executive officers of Mid Penn and their affiliates had the right to vote 1,620,890 shares of Mid Penn common stock, or 14.2% of the outstanding Mid Penn common stock entitled to be voted at the special meeting. Each of the directors and executive officers of Mid Penn have agreed to vote all shares of Mid Penn common stock owned by him or her that he or she, directly or indirectly, controls the right to vote and dispose of, in favor of the Mid Penn merger proposal.

Riverview Will Hold Its Special Meeting on Thursday, November 18, 2021 (page 102)

The Riverview special meeting will be held virtually via the internet at www.virtualshareholdermeeting.com/RIVE2021SM on November 18, 2021 at 10:00 a.m., Eastern Time. At the special meeting, Riverview shareholders will be asked to:

Record Date. Holders of Riverview common stock at the close of business on September 30, 2021 will be entitled to vote at the special meeting. Each share of Riverview common stock is entitled to one vote. As of the Riverview record date, there were 9,361,967 shares of Riverview common stock issued and outstanding and entitled to vote at the special meeting.

Required Vote. Assuming a quorum is present, approval of the Riverview merger proposal requires the affirmative vote of the holders of at least a majority of the votes cast at the Riverview special meeting. Failure to submit valid proxy instructions or to vote in person will have no effect on the Riverview merger proposal. Broker non-votes and abstentions from voting will have no effect on the Riverview merger proposal.

As of the record date, directors, executive officers and ten percent (10%) shareholders of Riverview and their affiliates had the right to vote 2,283,902 shares of Riverview common stock, or approximately 24.4% of the outstanding Riverview common stock entitled to be voted at the special meeting. Each of the directors, the executive officers and ten percent (10%) shareholders of Riverview have agreed to vote all shares of Riverview common stock owned by him, her or it in favor of adoption of the merger agreement.

Approval of the Riverview compensation proposal and the Riverview adjournment proposal require the affirmative vote of the holders of at least a majority of the votes cast at the Riverview special meeting. Failure to submit valid proxy instructions or to vote in person will have no effect on the Riverview compensation proposal or the Riverview adjournment proposal. Broker non-votes and abstentions from voting will have no effect on the Riverview compensation proposal or the Riverview adjournment proposal.

Riverview Shareholders Will Receive Shares of Mid Penn Common Stock in the Merger (page 82).

Upon completion of the merger, each outstanding share of Riverview common stock outstanding immediately prior to the effective time of the merger, will be converted into the right to receive 0.4833 shares of Mid Penn common stock, which we refer to as the “merger consideration.” The exchange ratio is fixed and not subject to adjustment, except in limited circumstances.

On June 29, 2021, which was the last trading date preceding the public announcement of the proposed merger, the closing price of Mid Penn common stock was $27.47 per share. On October 5, 2021, the most recent practicable trading day prior to the printing of this joint proxy statement/prospectus, the closing price of Mid Penn common stock was $27.89 per share. The market price of both Mid Penn common stock and Riverview common stock will fluctuate before the completion of the merger; therefore, you are urged to obtain current market quotations for Mid Penn common stock and Riverview common stock. The value of the merger consideration will fluctuate as the market price of Mid Penn common stock fluctuates before the completion of the merger. The market price of Mid Penn common stock at closing will not be known at the time of the Riverview special meeting and may be more or less than the current price of Mid Penn common stock or the price of Mid Penn common stock at the time of the Riverview special meeting or at the effective time of the merger.

Expected Material United States Federal Income Tax Treatment as a Result of the Merger (page 95)

The merger is structured to be treated as a reorganization for United States federal income tax purposes. Each of Mid Penn and Riverview has conditioned the consummation of the merger on its receipt of a legal opinion that this will be the case. Because Riverview shareholders will receive solely Mid Penn common stock for their shares (except for cash in lieu of fractional shares), Riverview shareholders should not recognize gain or loss except with respect to the cash they receive instead of a fractional share.

This tax treatment may not apply to all Riverview shareholders. Determining the actual tax consequences of the merger to Riverview shareholders can be complicated. Riverview shareholders should consult their own tax advisor for a full understanding of the merger’s tax consequences that are particular to each shareholder.

Exceptions to these conclusions or other considerations may apply, some of which are discussed beginning on page 95. Determining the actual tax consequences of the merger to a Riverview shareholder can be complicated. For further information, please refer to “Material United States Federal Income Tax Consequences of theMerger” on page 95.

Accounting Treatment of the Merger (page 94)

Mid Penn will account for this transaction as a business combination under the acquisition method. On the acquisition date, Mid Penn will record at fair value the identifiable assets acquired and the liabilities assumed, any noncontrolling interest, and goodwill (or a gain from a bargain purchase). The results of operations for the combined company will be reported prospectively subsequent to the acquisition date.

Market Prices and Share Information (page 113)

Mid Penn common stock is listed on The Nasdaq Global Select Market under the symbol “MPB.” Riverview common stock is quoted on the Nasdaq Global Select Market under the symbol “RIVE.”

The table below shows the last sale price of Mid Penn common stock and Riverview common stock, and the value of Mid Penn common stock received per share of Riverview common stock based upon the exchange ratio, on June 29, 2021 (the last full trading day prior to announcement of the execution of the merger agreement) and October 5, 2021 (the latest practicable trading day prior to the date of these materials).

Because the exchange ratio is fixed and will be adjusted only in limited circumstances, including if Mid Penn declares any stock dividends or effects a stock split or reverse stock split, and the market price of Mid Penn common stock will fluctuate prior to the merger, the pro forma equivalent price per share of Riverview common stock will also fluctuate prior to the merger. Riverview shareholders will not know the final equivalent price per share of Riverview common stock when they vote on the merger. This information relates to the value of shares of Riverview common stock that will be converted into shares of Mid Penn common stock in the merger. You should obtain current stock price quotations for the shares.

Following completion of the merger, current Mid Penn shareholders will own in the aggregate approximately 71.8% of the outstanding shares of Mid Penn common stock and Riverview shareholders will own approximately 28.2% of the outstanding shares of Mid Penn common stock.

Opinion of Riverview’s Financial Advisor (page 50)

At the June 30, 2021 meeting at which the Riverview board of directors considered and approved the merger agreement, Riverview’s financial advisor, Janney Montgomery Scott LLC, or Janney, delivered its oral opinion to Riverview’s board of directors, which was subsequently confirmed in writing, to the effect that, as of June 30, 2021, subject to the procedures followed, assumptions made, matters considered and qualifications and limitations described in Janney’s opinion, the exchange ratio was fair, from a financial point of view, to Riverview common equity shareholders.

The full text of Janney’s opinion is attached as Annex B to this joint proxy statement/prospectus. The opinion outlines the procedures followed, assumptions made, matters considered and qualifications and limitations on the review undertaken by Janney in rendering its opinion.

Riverview shareholders should read the opinion and the summary description of Janney’s opinion contained in this joint proxy statement/prospectus carefully in their entirety.

Janney’s opinion speaks only as of the date of the opinion. The opinion of Janney does not reflect any developments that may have occurred or may occur after the date of its opinion and prior to the completion of the merger. Riverview does not expect that it will request an updated opinion from Janney.

The opinion was directed to Riverview’s board of directors in connection with its consideration of the merger and is directed only as to the fairness, from a financial point of view, of the merger consideration to Riverview common equity shareholders. Janney’s opinion does not constitute a recommendation to any Riverview shareholder as to how such shareholder should vote at any meeting of shareholders called to consider and vote upon the Riverview merger proposal. Janney’s opinion does not address the underlying business decision of Riverview to engage in the merger, the form or structure of the merger, the relative merits of the merger as compared to any other alternative business strategies that might exist for Riverview or the effect of any other transaction in which Riverview might engage. Janney did not express any opinion as to the fairness of the amount or nature of the compensation plans,to be received in the merger by Riverview’s officers, directors, or employees, or class of such persons, if any, relative to the compensation to be received in the merger by any other shareholder of Riverview.

For further information, see “The Merger—Opinion of Riverview’s Financial Advisor.”

Opinion of Mid Penn’s Financial Advisor (page 62)

At the June 30, 2021 meeting at which the Mid Penn board of directors considered and approved the merger agreement, Mid Penn’s financial advisor, Stephens Inc., or Stephens, delivered its oral opinion to Mid Penn’s board of directors, which was subsequently confirmed in writing, to the effect that, as of June 30, 2021, subject to the procedures followed, assumptions made, matters considered and qualifications and limitations described in Stephens’s opinion, the merger consideration was fair, from a financial point of view, to Mid Penn.

The full text of Stephens’s opinion is attached as Annex C to this joint proxy statement/prospectus. The opinion outlines the procedures followed, assumptions made, matters considered and qualifications and limitations on the review undertaken by Stephens in rendering its opinion.

Mid Penn shareholders should read the opinion and the summary description of Stephens’s opinion contained in this joint proxy statement/prospectus carefully in their entirety.

Stephens’s opinion speaks only as of the date of the opinion. The opinion of Stephens does not reflect any developments that may have occurred or may occur after the date of its opinion and prior to the completion of the merger. Mid Penn does not expect that it will request an updated opinion from Stephens. The opinion was directed to Mid Penn’s board of directors in connection with its consideration of the merger and is directed only as to the fairness, from a financial point of view, of the merger consideration to Mid Penn. Stephens’s opinion does not constitute a recommendation to any Mid Penn shareholder as to how such shareholder should vote at any meeting of shareholders called to consider and vote upon the Mid Penn merger proposal. Stephens’s opinion does not address the underlying business decision of Mid Penn to engage in the merger, the form or structure of the merger, the relative merits of the merger as compared to any other alternative business strategies that might exist for Mid Penn or the effect of any other transaction in which Mid Penn might engage. Stephens did not express any opinion as to the fairness of the amount or nature of the compensation to be received in the merger by Mid Penn’s officers, directors, or employees, or class of such persons, if any, relative to the compensation to be received in the merger by any other shareholder of Mid Penn.

For further information, see “The Merger—Opinion of Mid Penn’s Financial Advisor.”

Board of Directors and Executive Officers of Mid Penn after the Merger (page 73)

Following completion of the merger, the then current directors and executive officers of Mid Penn and Mid Penn Bank will continue in office and the boards of directors of Mid Penn and Mid Penn Bank will be increased by two and three directors, respectively, and two of the current directors of Riverview selected by the board of directors of Riverview, with the approval of Mid Penn’s board of directors, will be added to the board of

directors of Mid Penn and three of the current directors of Riverview selected by the board of directors of Riverview, with the approval of Mid Penn’s board of directors, will be added to the board of directors of Mid Penn Bank.

The Mid Penn Board of Directors Recommends That Mid Penn Shareholders Vote “FOR” the Mid Penn Merger Proposal (page 100)

The Mid Penn board of directors believes that the merger is in the best interests of Mid Penn and has unanimously approved the merger and the merger agreement. The Mid Penn board of directors recommends that Mid Penn shareholders vote “FOR” approval of the Mid Penn merger proposal. The Mid Penn board also recommends that its shareholders vote “FOR” the Mid Penn adjournment proposal.

The Riverview Board of Directors Recommends That Riverview Shareholders Vote “FOR” the Riverview Merger Proposal and “FOR” the Riverview Compensation Proposal (page 104)

The Riverview board of directors believes that the merger is in the best interests of Riverview and has unanimously approved the merger and the merger agreement. The Riverview board of directors recommends that Riverview shareholders vote “FOR” the Riverview merger proposal. The Riverview board of directors also recommends a vote “FOR” approval of the Riverview compensation proposal and the Riverview adjournment proposal.

Riverview’s Directors and Executive Officers Have Financial Interests in the Merger that May Differ from the Interests of Riverview Shareholders (page 76)

In addition to their interests as Riverview shareholders, the directors and certain executive officers of Riverview have interests in the merger that are different from or in addition to interests of other Riverview shareholders. These interests include, among other things:

Riverview’s board of directors was aware of these interests and took them into account in its decision to approve the agreement and plan of merger. For information concerning these interests, please see the discussion on page 76 under the caption “Interests of Riverview’s Directors and Executive Officers in theMerger.” For more information concerning the closing conditions of the merger, please see the discussion on page 85 under the caption “The Merger Agreement—Covenants and Agreements.”

Riverview Shareholders’ Dissenters Rights to Appraisal Rights (page 74)

Under Pennsylvania law, Riverview shareholders have the right to dissent from the merger agreement and the merger and to receive a payment in cash for the “fair value” of their shares of Riverview common stock as determined by an appraisal process. This value may be more or less than the value you would receive in the merger if you do not dissent. If you dissent, you will receive a cash payment for the value of your shares that will be fully taxable to you. To perfect your dissenters’ rights, you must follow precisely the required statutory

procedures. See “Riverview Shareholders Have Dissenters’ Rights in the Merger” beginning on page 74 as well as the numberfull text of securities remaining availableSections 1571 through 1580 of the Pennsylvania Business Corporation Law of 1988, as amended, which are attached to this joint proxy statement/prospectus as Annex D.

The Rights of Riverview Shareholders Will Change After the Merger (page 108)

The rights of Riverview shareholders will change as a result of the merger due to differences in Mid Penn’s and Riverview’s governing documents. The rights of Riverview’s shareholders are governed under Pennsylvania law and by Riverview’s articles of incorporation and bylaws. Upon completion of the merger, Riverview shareholders will be governed under Pennsylvania law and by Mid Penn’s articles of incorporation and bylaws. A description of shareholder rights under each of the Mid Penn and Riverview governing documents, and the material differences between them, is included in the section entitled “Comparison of Shareholders’ Rights” found on page 108.

Conditions That Must Be Satisfied or Waived for future issuancethe Merger to Occur (page 75)

Currently, we expect to complete the merger in the fourth quarter of 2021. In addition to the approval of the merger proposal by the requisite vote of Mid Penn and Riverview shareholders and the receipt of all required regulatory approvals and expiration or termination of all statutory waiting periods in respect thereof, each as described herein, each party’s obligation to complete the merger is also subject to the satisfaction or waiver (to the extent permitted under applicable law) of certain other conditions, including the effectiveness of the registration statement containing this joint proxy statement/prospectus, approval of the listing on the Nasdaq Stock Market of the Mid Penn common stock to be issued in the merger, the absence of any applicable law or order prohibiting the merger, the accuracy of the representations and warranties of the other party under the merger agreement (subject to the materiality standards set forth in the merger agreement), the performance by the other party of its respective obligations under the merger agreement in all material respects, delivery of officer’s certificates by the other party certifying satisfaction of the two preceding conditions and each of Mid Penn’s and Riverview’s receipt of a tax opinion to the effect that the merger will be treated as a “reorganization” within the meaning of Section 368(a) of the Code.

Neither Riverview nor Mid Penn can be certain when, or if, the conditions to the merger will be satisfied or waived, or that the merger will be completed.

No Solicitation of Other Offers (page 88)

Riverview has agreed that it will not, and Riverview will cause its subsidiaries and each of their respective officers, directors, employees, representatives, agents, and affiliates not to, except as otherwise expressly permitted in the merger agreement, between the date of the merger agreement and the closing of the merger, directly or indirectly:

The merger agreement does not, however, prohibit Riverview from furnishing information or access to a third party who has made an unsolicited alternative acquisition proposal and participating in discussions and negotiating with such plans,person if specified conditions are met. Among those conditions is a good faith determination by Riverview’s board of directors that the acquisition proposal constitutes or that could reasonably be expected to lead to a proposal that is more favorable, from a financial point of view, to Riverview and its shareholders than the transactions contemplated by the merger agreement and is reasonably capable of being completed on its stated terms, taking into account all financial, regulatory, legal and other aspects of the proposal.

For further discussion of the restrictions on solicitation of acquisition proposals from third parties, see “The Merger Agreement—Agreement Not to Solicit Other Offers” beginning on page 88.

Termination of the Merger Agreement (page 92)

We may mutually agree to terminate the merger agreement before completing the merger, even after Riverview or Mid Penn shareholder approval. In addition, either of us may decide to terminate the merger agreement, if (i) a court or governmental entity issues a final order that is not appealable prohibiting the merger, (ii) a bank regulator which must grant a regulatory approval as a condition to the merger denies such approval of the merger and such denial has become final and is not appealable, (iii) the shareholders of Mid Penn or Riverview fail to approve the merger at their respective special meetings, or (iv) the other party breaches the merger agreement in a way that would entitle the party seeking to terminate the agreement not to consummate the merger, subject to the right of the breaching party to cure the breach within thirty (30) days following written notice. Either of us may terminate the merger agreement if the merger has not been completed by March 31, 2022, unless the reason the merger has not been completed by that date is a breach of the merger agreement by the company seeking to terminate the merger agreement.

Mid Penn may terminate the merger agreement if the Riverview board of directors, in connection with the receipt of a superior alternative acquisition proposal, (1) enters into a letter of intent, agreement in principle or an acquisition agreement with respect to the superior alternative acquisition proposal, (2) fails to make, withdraws, modifies or qualifies its recommendation of the merger agreement in a manner adverse to Mid Penn, or (3) has otherwise made a determination to accept the superior alternative acquisition proposal.

Riverview may terminate the merger agreement if Riverview receives an alternative acquisition proposal and has made a determination that the alternative acquisition proposal is a superior proposal and accepts such alternative acquisition proposal.

Riverview may also terminate the merger agreement on or after the fifth business day (the “determination date”) immediately prior to the closing date of the merger if the quotient obtained by dividing (A) the average of the per share closing price of a share of Mid Penn common stock during the 20 consecutive full trading days ending on the trading date prior to the determination date by (B) $27.95 is both (i) less than 0.80 and (ii) less (by more than 20%) than the quotient obtained by dividing (Y) the average of the NASDAQ Bank Index Value during the 20 consecutive full trading days ending on the trading date prior to the determination date by (Z) $4,579.01. If Riverview chooses to exercise this termination right, Mid Penn has the option, within two business days of receipt of notice from Riverview, to adjust the merger consideration and prevent termination under this provision.

Termination Fee (page 93)

Riverview will pay Mid Penn a termination fee of $5,070,000 if the merger agreement is terminated:

Riverview will also be required to pay Mid Penn the termination fee of $5,070,000 in the event that Riverview enters into a definitive agreement relating to, or consummates, an acquisition proposal within twelve (12) months following termination of the merger agreement:

Regulatory Approvals Required for the Merger (page 75)

Completion of the merger and the bank merger are subject to the receipt of all approvals required by, or waivers from, applicable regulatory authorities. The transaction is subject to approval by the Federal Deposit Insurance Corporation (the “FDIC”) and the Pennsylvania Department of Banking and Securities (the “PDB”) and approval, or waiver of formal application and approval requirements, fromthe Board of Governors of the Federal Reserve System (the “FRB”). Mid Penn has filed or will file all required applications, notices and waiver requests to obtain the regulatory approvals and non-objections necessary to consummate the merger. While Mid Penn does not know of any reason why it would not obtain the approvals in a timely manner, Mid Penn cannot be certain when or if it will receive the regulatory approvals.

Notifications and/or applications requesting approval may also be submitted to various other federal and state regulatory authorities and self-regulatory organizations. Mid Penn and Riverview have agreed to use their reasonable best efforts to obtain all required regulatory approvals.

Risk Factors (page 32)

You should consider all the information contained in or incorporated by reference into this joint proxy statement/prospectus in deciding how to vote for the proposals presented in the joint proxy statement/prospectus. In particular, you should consider the factors described under “Risk Factors.”

UNAUDITED PRO FORMA COMBINED CONSOLIDATED FINANCIAL INFORMATION

The unaudited pro forma combined condensed consolidated financial information has been prepared using the acquisition method of accounting, giving effect to Mid Penn’s proposed acquisition of Riverview. Under this method, Riverview’s assets and liabilities as of the date of the acquisition will be recorded at their respective fair values and added to those of Mid Penn. Any difference between the purchase price for Riverview and the fair value of the identifiable net assets acquired (including core deposit intangibles) will be recorded as goodwill. The goodwill resulting from the acquisition will not be amortized to expense, but instead will be reviewed for impairment at least annually. Any core deposit intangible and other intangible assets with estimated useful lives to be recorded by Mid Penn in connection with the acquisition will be amortized to expense over their estimated useful lives. The financial statements of Mid Penn issued after the acquisition will reflect the results attributable to the acquired operations of Riverview beginning on the date of completion of the acquisition.

The unaudited pro forma combined condensed financial statements have been prepared in accordance with Article 11 of Regulation S-X, Pro Forma Information, as amended by the final rule, Amendments to Financial Disclosures About Acquired and Disposed Businesses, as adopted by the SEC on May 21, 2020, which requires the depiction of the accounting for the transaction, which we refer to as transaction accounting adjustments, and presentation of the reasonably estimable cost savings and revenue enhancements and other transaction effects that have occurred or are reasonably expected to occur, which we refer to as management’s adjustments. Mid Penn has elected not to present management’s adjustments and will only be presenting transaction accounting adjustments in the following unaudited pro forma condensed combined financial information.

The following unaudited pro forma combined consolidated balance sheet as of June 30, 2021 and income statements for both (i) the twelve months ended December 31, 2018.2020 and (ii) the six months ended June 30, 2021 combine the historical financial statements of Mid Penn and Riverview. The unaudited pro forma consolidated financial statements give effect to the proposed acquisition as if the acquisition occurred on June 30, 2021 with respect to the balance sheet, and at the beginning of the periods for both the year ended December 31, 2020 and the six months ended June 30, 2021, with respect to the statement of operations. The unaudited pro forma consolidated financial statements were prepared with Mid Penn as the acquirer and Riverview as the acquiree under the acquisition method of accounting. Accordingly, the consideration paid by Mid Penn to complete the acquisition of Riverview will be allocated to Riverview’s assets and liabilities based upon their estimated fair values as of the date of completion of the acquisition. The allocation is dependent upon certain valuations and other studies that have not been finalized at the time of the acquisition announcement; however, preliminary valuations based on the fair value of the acquired assets and liabilities have been estimated and included in the unaudited pro forma financial statements.

The final allocation of the purchase price will be determined after the merger is completed and after completion of thorough analyses to determine the fair value of Riverview’s tangible and identifiable intangible assets and liabilities as of the date the merger is completed. Increases or decreases in the estimated fair values of the net assets as compared with the information shown in the unaudited pro forma combined condensed consolidated financial information may change the amount of the purchase price allocated to goodwill and other assets and liabilities and may impact Mid Penn’s consolidated statement of operations due to adjustments in yield and/or amortization of the adjusted assets or liabilities. Any changes to Riverview’s shareholders’ equity, including results of operations from June 30, 2021 through the date the merger is completed will also change the purchase price allocation, which may include the recording of a lower or higher amount of goodwill. The final adjustments may be materially different from the unaudited transaction accounting adjustments presented herein. The pro forma calculations, shown herein, assume a closing price for Mid Penn common stock of $27.45, which represents the closing price of Mid Penn common stock on June 30, 2021.

The pro forma income statement and per share data information does not include anticipated cost savings or revenue enhancements, nor does it include one-time merger-related expenses which will be expensed against income. Riverview and Mid Penn are currently in the process of assessing the two companies’ personnel, benefits

plans, premises, equipment, computer systems and service contracts to determine where the companies may take advantage of redundancies or where it will be beneficial or necessary to convert to one system. Certain decisions arising from these assessments may involve canceling contracts between either Riverview or Mid Penn and certain service providers. There is no assurance that the anticipated cost savings will be realized on the anticipated time schedule or at all.

The pro forma combined basic and diluted earnings per share of Mid Penn common stock is based on the pro forma combined net income per common share for Riverview and Mid Penn divided by the pro forma basic or diluted common shares of the combined entities. The pro forma information includes adjustments related to the fair value of assets and liabilities of Riverview and is subject to adjustment as additional information becomes available and as final merger date analyses are performed. The pro forma combined balance sheet and book value per share data does include the impact of merger-related expenses on the balance sheet with Riverview’s after-tax charges currently estimated at $3,213,000, illustrated as an adjustment to accrued other liabilities, and Mid Penn’s after-tax estimated charges of $11,967,000, illustrated as an adjustment to retained earnings and to accrued other liabilities. The pro forma combined book value and tangible book value of Mid Penn common stock is based on the pro forma combined common stockholders’ equity of Riverview and Mid Penn divided by total pro forma common shares of the combined entities.

Certain reclassification adjustments have been made to Riverview’s financial statements to conform to Mid Penn’s financial statement presentation. The unaudited pro forma information, while helpful in illustrating the financial characteristics of the combined company under one set of assumptions, does not reflect the benefits of expected cost savings or opportunities to earn additional revenue and, accordingly, does not attempt to predict or suggest future results. It also does not necessarily reflect what the historical results of the combined company would have been had our companies been combined during this period.

Additionally, the information presented should be read together with the historical consolidated financial statements of Mid Penn and Riverview, including the related notes, which are based on and should be read in conjunction with (i) the historical audited consolidated financial statements of each of Mid Penn and Riverview, and the related notes, included in such party’s Annual Report on Form 10-K for the year ended December 31, 2020, which are incorporated by reference herein and (ii) the historical unaudited consolidated financial statements of each of Mid Penn and Riverview for the period ended June 30, 2021, included in such party’s Quarterly Report on Form 10-Q for the period ended June 30, 2021, which are incorporated by reference herein. Additionally, see “Where You Can Find More Information” beginning on page 117.

The unaudited pro forma data are qualified by the statements set forth under this caption and should not be considered indicative of the market value of Mid Penn common stock or the actual or future results of operations of Mid Penn for any period. Actual results may be materially different than the pro forma information presented.

Pro Forma Combined Consolidated Balance Sheet as of June 30, 2021

Unaudited (Dollars in thousands, except share and per common share data)

Pro Forma Combined Consolidated Statement of Income

For the Six Months Ended June 30, 2021

Unaudited (Dollars in thousands, exept share and per common share data)