Exhibit 99.1

Mid Penn Bancorp, Inc.

2407 Park Drive

Harrisburg, PA 17110

1-866-642-7736

April 23, 2025 – Harrisburg, PA – Mid Penn Bancorp, Inc. (NASDAQ: MPB) ("Mid Penn"), the parent company of Mid Penn Bank (the "Bank") and MPB Financial Services, LLC, today reported net income available to common shareholders ("earnings") for the quarter ended March 31, 2025, of $13.7 million, or $0.71 per diluted common share, compared to net income of $12.1 million, or $0.73 per diluted common share, for the first quarter of 2024, and a consensus analyst estimate of $0.63 per diluted common share for the first quarter of 2025.

Key Highlights of the First Quarter of 2025:

•Net income available to common shareholders increased 13.3% to $13.7 million, or $0.71 per diluted common share, for the first quarter of 2025, compared to net income of $12.1 million, or $0.73 per diluted common share, for the first quarter of 2024. On a non-GAAP basis, core earnings(1) for the quarter ended March 31, 2025, increased 30.3% to $13.9 million, or $0.72 per diluted common share, compared to $10.7 million, or $0.64 per diluted common share, for the first quarter of 2024.

•Net interest margin increased to 3.37% for the quarter ended March 31, 2025, compared to 3.21% for the fourth quarter of 2024. Cost of funds decreased to 2.48% for the quarter ended March 31, 2025, compared to 2.66% for the fourth quarter of 2024, as a result of a decrease in interest paid on interest-bearing deposit accounts, driven by the Bank lowering rates in response to the Federal Reserve interest rate cuts in the third and fourth quarters of 2024. The yield on loans decreased to 6.05% for the quarter ended March 31, 2025, compared to 6.10% for the fourth quarter of 2024. Net interest margin increased to 3.37% for the quarter ended March 31, 2025, compared to 2.97% for the first quarter of 2024, representing a 40 bp increase compared to the same period in 2024.

•Loan growth for the first quarter of 2025 was $48.1 million, or 4.4% (annualized), as the Bank continued to execute on its restrained growth strategy in 2025. Total loans increased $173.7 million, or 4.0% to $4.5 billion at March 31, 2025, compared to $4.3 billion at March 31, 2024.

•Deposits increased $42.3 million, or 3.7% (annualized), during the first quarter of 2025, compared to a decrease of $16.8 million, or 1.4% (annualized), during the fourth quarter of 2024. This increase was driven by a $55.5 million increase in interest-bearing transaction accounts, a $29.1 million increase in noninterest-bearing accounts, offset by $42.3 million decrease in time deposits. Total deposits increased $353.1 million or 8.06% to $4.7 billion at March 31, 2025, compared to $4.4 billion at March 31, 2024.

•Book value per common share improved to $34.50 as of March 31, 2025, compared to $33.84 and $33.26 as of December 31, 2024 and March 31, 2024, respectively. Tangible book value per common share (1) improved to $27.58 for as of March 31, 2025, compared to $26.90 and $25.23 as of December 31, 2024 and March 31, 2024, respectively.

•The core efficiency ratio(1) improved to 62.79% in the first quarter of 2025, compared to 63.9% in the fourth quarter of 2024, and 68.8% in the first quarter of 2024.

•As a result of the foregoing, the Board of Directors declared a cash dividend of $0.20 per common share, payable May 26, 2025, to shareholders of record as of May 8, 2025.

(1) Non-GAAP financial measure. Refer to the calculation in the section titled “Reconciliation of Non-GAAP Measures (Unaudited)” at the end of this document.

Chair, President and CEO Rory G. Ritrievi provided the following statement:

"It is with great pleasure that we announce our first quarter of 2025 performance, which in many ways is a continuation of what we were able to accomplish in 2024.

Despite a fairly tumultuous quarter for the nation and most of the world, we delivered a solid beat of consensus estimates on earnings per share. That beat was the result of healthy net interest margin expansion, moderate growth in both loans and deposits, strong asset quality performance and an improvement in the efficiency ratio.

The net interest margin expansion was achieved by a decrease in deposit costs resulting from repricing initiatives started in the fourth quarter of 2024 and continuing through the first quarter of 2025.

Even while increasing revenues around 3% annualized, we decreased operating expenses over 3% annualized, resulting in a 110 basis point, or almost 7% annualized, improvement in the efficiency ratio. Solid expense management continues.

Our commercial and consumer bankers across our expanding footprint delivered a respectable organic growth rate of 4.4% (annualized) in loans and 3.7% (annualized) in deposits. Those growth rates are a little less than what we had hoped for the quarter, but we recognize that our borrower’s and depositors are influenced by what they feel and see in the overall economy. Their sentiment in the first quarter would be best described as cautious.

In early April, we announced that we had received all regulatory approvals for our planned merger with William Penn Bank as well as the enthusiastic approval of both shareholder groups. As a result, we expect that the William Penn merger will close in the middle of the second quarter of 2025. We welcome all the William Penn customers and shareholders in advance of the expected completion.

In consideration of our first quarter success, the Board has authorized its 58th consecutive quarterly dividend, a cash dividend of $0.20 per share of common stock, which was declared at its meeting on April 23, 2025, payable on May 26, 2025, to shareholders of record as of May 8, 2025." For the three months ended March 31, 2025, net interest income was $42.5 million, compared to net interest income of $41.3 million for the three months ended December 31, 2024, and $36.5 million for the three months ended March 31, 2024.

Net Interest Income

The tax-equivalent net interest margin for the three months ended March 31, 2025, was 3.37% compared to 3.21% and 2.97% for the fourth quarter of 2024 and first quarter of 2024, respectively, representing a 16 basis point ("bp") increase from the fourth quarter of 2024, and a 40 bp increase compared to the same period in 2024.

The yield on interest-earning assets decreased to 5.65% for the quarter ended March 31, 2025, from 5.67% for the three months ended December 31, 2024, and increased from 5.51% for the three months ended March 31, 2024. The decrease from the fourth quarter of 2024 was primarily due to a decrease in the average balance of Federal Funds Sold and a decrease in interest income from loans as a result of lower rates, partially offset by an increase in taxable investment securities. The increase from March 31, 2024, was due to assets continuing to reprice at higher rates during 2024 and 2025, continued discipline on new loan pricing, and an overall increase in the average balance of Fed Funds Sold.

For the three months ended March 31, 2025, net interest income increased 16.6% to $42.5 million compared to net interest income of $36.5 million for the same period of 2024. The increase was primarily due to a $3.3 million increase in interest income on loans, a $420 thousand increase in income on investment securities, and a $4.2 million decrease in the interest paid on short term borrowings, offset by a $1.9 million increase in interest expense on deposits compared to the same period of 2024.

Average Balances

Average loans increased $18.2 million to $4.5 billion for the quarter ended March 31, 2025, compared to $4.4 billion for the quarter ended December 31, 2024, and $4.3 billion for the quarter ended March 31, 2024.

Average deposits were $4.7 billion for the first quarter of 2025, reflecting a decrease of $6.2 million, or 0.1%, compared to total average deposits of $4.7 billion in the fourth quarter of 2024, and an increase of $369.6 million, or 8.6%, compared to total average deposits of $4.3 billion for the first quarter of 2024. The average cost of deposits was 2.45% for the first quarter of 2025, representing a 20 bp decrease and a 2 bp increase from the fourth quarter of 2024 and the first quarter of 2024, respectively. The Bank continues to face headwinds with respect to deposit pricing, given competition for deposits across all product types. Our primary focus with respect to deposit strategy is stability, ensuring that our rates are competitive, and our product mix satisfies the needs of our customers. Additionally, the Bank also maintains interest rate swaps to hedge the cash flow risk associated with existing brokered CDs, and to mitigate the impact of higher deposit costs. Cost of funds decreased to 2.48%, compared to 2.66% for the fourth quarter of 2024, as a result of a $2.6 million decrease in interest paid on interest-bearing deposit accounts due to the Bank lowering rates in response to the Federal Reserve interest rate cuts in the third and fourth quarters of 2024.

Asset Quality

The total provision for credit losses, including provision for credit losses on off-balance sheet credit exposures, was $301 thousand for the three months ended March 31, 2025, a decrease of $32 thousand compared to the provision for credit losses of $333 thousand for the three months ended December 31, 2024, and a $1.2 million increase compared to the benefit for credit losses of $937 thousand for the three months ended March 31, 2024. This decrease from the three months ended December 31, 2024, was driven by decreases in loss rates across multiple segments of the portfolio, offset by increased reserves on individually evaluated loans. Net recoveries for the three months ended March 31, 2025, were $3 thousand or less than 0.0001% of total average loans.

The provision for credit losses on loans was $321 thousand for the three months ended March 31, 2025, an increase of $940 thousand compared to the benefit for credit losses of $619 thousand for the three months ended March 31, 2024. This increase for the three months ended March 31, 2025, was primarily due to an increase in loss factors across certain portfolios. The benefit for credit losses on off-balance sheet credit exposures was $20 thousand for the three months ended March 31, 2025.

Allowance for credit losses - loans was 0.80%, 0.80%, and 0.78% of loans, net of unearned income at March 31, 2025, December 31, 2024, and March 31, 2024, respectively.

Total nonperforming assets were $25.4 million at March 31, 2025, compared to nonperforming assets of $22.7 million and $15.5 million at December 31, 2024, and March 31, 2024, respectively. The increase during the first quarter of 2025 primarily related to the addition of three commercial loans with a combined balance of $7.0 million, partially offset by the payoff of two commercial loans with a combined balance of $3.0 million. Delinquency, measured as loans past due 30 days or more, as a percentage of total loans was 0.50% at March 31, 2025, compared to 0.52% and 0.38% as of December 31, 2024, and March 31, 2024, respectively.

Capital

Shareholders’ equity increased $12.9 million, or 2.0%, from $655.0 million as of December 31, 2024, to $667.9 million as of March 31, 2025. Retained earnings increased $9.9 million, or 5.4%, from $181.6 million as of December 31, 2024, to $191.5 million as of March 31, 2025. Regulatory capital ratios for both Mid Penn and the Bank indicate regulatory capital levels in excess of both the regulatory minimums and the levels necessary for the Bank to be considered "well capitalized" at March 31, 2025. Additionally, Mid Penn declared $3.9 million in dividends during the first quarter of 2025.

On April 23, 2025, Mid Penn’s Board of Directors reauthorized its treasury stock repurchase program ("The Program") effective through April 30, 2026. The Program authorizes the repurchase of up to $15.0 million of Mid Penn’s outstanding common stock. As of March 31, 2025, Mid Penn repurchased a total of 440,722 shares of common stock at an average price of $22.78 per share under the Program. No shares were purchased in the first quarter of 2025. The Program had approximately $5.0 million remaining available for repurchase as of March 31, 2025.

Noninterest Income

For the three months ended March 31, 2025, noninterest income totaled $5.2 million, a decrease of $910 thousand, or 14.8%, compared to noninterest income of $6.1 million for the fourth quarter of 2024. The decrease is primarily due to a $717 thousand decrease in other miscellaneous noninterest income, driven by a $532 thousand decrease in Bank-owned life insurance benefits received, and $106 million decrease in insurance commissions.

For the three months ended March 31, 2025, noninterest income totaled $5.2 million, a decrease of $598 thousand, or 10.2%, compared to noninterest income of $5.8 million for the three months ended March 31, 2024. The decrease in noninterest income is primarily driven by a $731 thousand decrease in other miscellaneous noninterest income, driven by a $1.4 million decrease in Bank-owned life insurance benefits received, partially offset by a $357 thousand increase in loan level swap fees, a $113 thousand increase in other letter of credit income, and a $167 thousand increase in Mortgage Banking income.

Noninterest Expense

Total noninterest expense decreased $272 thousand to $30.6 million in the first quarter of 2025 from $30.9 million in the fourth quarter of 2024. The decrease was driven by a $638 thousand decrease in salaries and employee benefits, driven by a decrease in bonuses paid, partially offset by a $514 thousand increase in shares tax.

For the three months ended March 31, 2025, noninterest expense totaled $30.6 million, an increase of $2.1 million, or 7.4%, compared to noninterest expense of $28.5 million for the three months ended March 31, 2024. The increase was primarily driven by a $847 thousand increase in salaries and employee benefits, a $454 thousand increase in software licensing, a $314 thousand increase in merger and acquisition expenses, and a $292 thousand increase in occupancy expenses, partially offset by a $172 thousand decrease in legal and professional fees.

The core efficiency ratio(1) was 62.8% in the first quarter of 2025, compared to 63.9% in the fourth quarter of 2024, and 68.8% in the first quarter of 2024. The change in the core efficiency ratio during the first quarter of 2025 compared to the fourth quarter of 2024 was the result of slightly higher net interest income, partially offset by lower noninterest income, and slightly lower noninterest expense. Mid Penn continues to evaluate levels of noninterest expense for opportunities to reduce operating costs throughout the organization.

(1)Non-GAAP financial measure. Refer to the calculation in the section titled “Reconciliation of Non-GAAP Measures (Unaudited)” at the end of this document. Non-GAAP financial measure.

Subsequent Events

Management considers subsequent events occurring after the balance sheet date for matters which may require adjustment to, or disclosure in, the consolidated financial statements. The review period for subsequent events extends up to and including the filing date of a public company’s consolidated financial statements when filed with the Securities and Exchange Commission ("SEC"). Accordingly, the financial information in this announcement is subject to change. The statements are valid only as of the date hereof and Mid Penn disclaims any obligation to update this information.

On April 2, 2025, Mid Penn and William Penn Bancorporation ("William Penn") announced that shareholders of both companies overwhelmingly approved Mid Penn's proposed acquisition of William Penn. The approvals were obtained at special meetings of shareholders held by each company on April 2, 2025.

This press release, and oral statements made regarding the subjects of this release, contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Such statements are not historical facts and include expressions about management's confidence and strategies and management's current views and expectations about new and existing programs and products, relationships, opportunities, technology, and market conditions. These statements may be identified by such forward-looking terminology as "continues," "expect," "look," "believe," "anticipate," "may," "will," "should," "projects," "strategy" or similar statements. Actual results may differ materially from such forward-looking statements, and no reliance should be placed on any forward-looking statement. Factors that may cause results to differ materially from such forward-looking statements include, but are not limited to, changes in interest rates, spreads on earning assets and interest-bearing liabilities, and interest rate sensitivity; prepayment speeds, loan originations, credit losses and market values on loans, collateral securing loans, and other assets; sources of liquidity; common shares outstanding; common stock price volatility; fair value of and number of stock-based compensation awards to be issued in future periods; the impact of changes in market values on securities held in Mid Penn’s portfolio; legislation affecting the financial services industry as a whole, and Mid Penn and Mid Penn Bank individually or collectively, including tax legislation; results of the regulatory examination and supervision process and oversight, including changes in monetary policy and capital requirements; changes in accounting policies or procedures as may be required by the Financial Accounting Standards Board or regulatory agencies; increasing price and product/service competition by competitors, including new entrants; rapid technological developments and changes; the ability to continue to introduce competitive new products and services on a timely, cost-effective basis; the mix of products/services; containing costs and expenses; governmental and public policy changes; protection and validity of intellectual property rights; reliance on large customers; technological, implementation and cost/financial risks in large, multi-year contracts; the outcome of future litigation and governmental proceedings, including tax-related examinations and other matters; continued availability of financing; the availability of financial resources in the amounts, at the times and on the terms required to support Mid Penn and Mid Penn Bank’s future businesses; material differences in the actual financial results of merger, acquisition and investment activities compared with Mid Penn’s initial expectations, including the full realization of anticipated cost savings and revenue enhancements; the occurrence of any event, change or other circumstances that could give rise to the right of one or both of the parties to terminate the merger agreement between Mid Penn and William Penn; the outcome of any legal proceedings that may be instituted against Mid Penn or William Penn; delays in completing the transaction; the failure to satisfy any of the other conditions to the transaction on a timely basis or at all; the possibility that the transaction may be more expensive to complete than anticipated, including as a result of unexpected factors or events; the possibility that the anticipated benefits of the transaction are not realized when expected or at all, including as a result of the impact of, or problems arising from, the integration of the two companies or as a result of the strength of the economy and competitive factors in legacy Mid Penn and target markets; diversion of management’s attention from ongoing business operations and opportunities; potential adverse reactions or changes to business or employee relationships, including those resulting from the announcement or completion of the transaction; the ability to complete the integration of Mid Penn and William Penn successfully; the dilution caused by Mid Penn’s issuance of additional shares of its capital stock in connection with the transaction; and other factors that may affect the future results of Mid Penn or William Penn.

For a more detailed description of these and other factors which would affect our results, please see Mid Penn’s filings with the SEC, including those risk factors identified in the "Risk Factors" section and elsewhere in our Annual Report on Form 10-K for the year ended December 31, 2024 and subsequent filings with the SEC. The statements in this press release are made as of the date of this press release, even if subsequently made available by Mid Penn on its website or otherwise. Mid Penn does not undertake, and specifically disclaims any obligation, to publicly release the result of any revisions which may be made to forward-looking statements to reflect events or circumstances after the date of such statements or to reflect the occurrence of unanticipated events, except as required by law.

(1)Non-GAAP financial measure. Refer to the calculation in the section titled “Reconciliation of Non-GAAP Measures (Unaudited)” at the end of this document.

(2)Regulatory capital ratios as of March 31, 2025 are preliminary and prior periods are actual.

(3)Annualized ratio

(1)Presented on a fully taxable-equivalent basis using a 21% federal tax rate and statutory interest expense disallowance.

(2)Annualized ratios

Explanatory note: This press release contains financial information determined by methods other than in accordance with U.S. Generally Accepted Accounting Principles ("GAAP"). Mid Penn’s management uses these non-GAAP financial measures in their analysis of Mid Penn’s performance. For tangible book value, the most directly comparable financial measure calculated in accordance with GAAP is book value. We believe that this measure is important to many investors in the marketplace who are interested in changes from period to period in book value per common share exclusive of changes in intangible assets. Goodwill and other intangible assets have the effect of increasing total book value while not increasing tangible book value. Income tax effects of non-GAAP adjustments are calculated using the applicable statutory tax rate for the jurisdictions in which the charges (benefits) are incurred, while taking into consideration any valuation allowances or non-deductible portions of the non-GAAP adjustments. Adjusted earnings per common share excludes from income available to common shareholders certain expenses related to significant non-core activities, including merger-related expenses, net of income taxes. For return on average tangible common equity, the most directly comparable financial measure calculated in accordance with GAAP is return on average equity. The core efficiency ratio is often used by management to measure its noninterest expense as a percentage of its revenue. This non-GAAP disclosure has limitations as an analytical tool, should not be viewed as a substitute for financial measures determined in accordance with GAAP, and should not be considered in isolation or as a substitute for analysis of Mid Penn’s results and financial condition as reported under GAAP, nor is it necessarily comparable to non-GAAP performance measures that may be presented by other companies. Management believes that this non-GAAP supplemental information will be helpful in understanding Mid Penn’s ongoing operating results. This supplemental presentation should not be construed as an inference that Mid Penn’s future results will be unaffected by similar adjustments to be determined in accordance with GAAP. The reconciliation of the non-GAAP to comparable GAAP financial measures can be found in the tables below.

(1) Annualized ratio