Other Events. The board of directors of S&T Bancorp, Inc. (S&T), the holding company for S&T Bank, approved a $0.37 per share cash dividend on August 5, 2026. A copy of the press release is attached hereto as Exhibit 99.1 . This is an increase of $0.03, or 8.82 percent, compared to a cash dividend of $0.34 per share declared in the same period in the prior year. The annualized yield using the August 4, 2026, closing price of $52.68 is 2.81 percent. The dividend is payable August 27, 2026 to s…

of this Report on Form 8-K, including Exhibit 99.1 , is being furnished and shall not be deemed "filed" for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall such information be deemed incorporated by reference in any filing under the Securities Exchange Act of 1933, as amended (the “Securities Act”), or the Exchange Act, except as shall be expressly set forth by specific reference…

Other Events. On July 23, 2026 S&T announced that the Board authorized a new $100 million share repurchase program at its meeting held July 22, 2026. The new program is set to expire on August 31, 2027. The remaining capacity under the existing share repurchase program was terminated. The new program will replace the existing share repurchase program effective July 27, 2026. This repurchase authorization permits S&T to repurchase shares of S&T's common stock from time to time through a combin…

member of the Audit Committee, Compensation and Benefits Committee, and Technology and Operations Committee — Stephanie Nycum Doliveira: Ms. Doliveira was appointed to serve on multiple committees of the Board.

Other Events. The board of directors of S&T Bancorp, Inc. (S&T), the holding company for S&T Bank, approved a $0.37 per share cash dividend on April 29, 2026. A copy of the press release is attached hereto as Exhibit 99.1 . This is an increase of $0.01, or 2.78 percent, compared to a cash dividend of $0.36 per share declared in the prior quarter and an increase of $0.03, or 8.82 percent, compared to a cash dividend of $0.34 per share declared in the same period in the prior year. The annualiz…

of this Report on Form 8-K, including Exhibit 99.1, is being furnished and shall not be deemed "filed" for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall such information be deemed incorporated by reference in any filing under the Securities Exchange Act of 1933, as amended (the “Securities Act”), or the Exchange Act, except as shall be expressly set forth by specific reference…

Chief Executive Officer — Christopher McComish: Amended and restated employment agreement with enhanced compensation terms.

Other Events. The board of directors of S&T Bancorp, Inc. (S&T), the holding company for S&T Bank, approved a $0.36 per share cash dividend on January 28, 2026. A copy of the press release is attached hereto as Exhibit 99.1 . This is an increase of $0.02, or 5.88 percent, compared to a cash dividend of $0.34 per share declared in the same period in the prior year. The annualized yield using the January 27, 2026, closing price of $42.11 is 3.42 percent. The dividend is payable February 26, 202…

Other Events. On January 22, 2026, S&T also announced that the board authorized a new $100 million share repurchase program at its meeting held January 21, 2026. The new program will replace the existing share repurchase program effective January 26, 2026, and is set to expire February 1, 2027. The remaining capacity under the existing share repurchase program was terminated. The new program authorizes the share repurchase of S&T's common stock from time to time through a combination of open…

of this Report on Form 8-K, including Exhibit 99.1 , is being furnished and shall not be deemed "filed" for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall such information be deemed incorporated by reference in any filing under the Securities Exchange Act of 1933, as amended (the “Securities Act”), or the Exchange Act, except as shall be expressly set forth by specific reference…

Director — Stephanie Nycum Doliveira: The filing discloses the appointment of a new independent director to the Board, which is a standard governance action and not a departure of an existing executive.

Other Events. The Board of Directors of S&T Bancorp, Inc. (S&T), the holding company for S&T Bank, approved a $0.36 per share cash dividend on October 29, 2025. A copy of the press release is attached hereto as Exhibit 99.1 . This is an increase of $0.02, or 5.88 percent, compared to a cash dividend of $0.34 per share declared in the same period in the prior year. The annualized yield using the October 28, 2025, closing price of $37.04 is 3.89 percent. The dividend is payable November 28, 202…

of this Report on Form 8-K, including Exhibit 99.1, is being furnished and shall not be deemed "filed" for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall such information be deemed incorporated by reference in any filing under the Securities Exchange Act of 1933, as amended (the “Securities Act”), or the Exchange Act, except as shall be expressly set forth by specific reference…

Chair of the Board — Christine Toretti: The Chair of the Board is resigning to accept a government appointment, which is a significant leadership change but not a negative operational event.

Other Events. The Board of Directors of S&T Bancorp, Inc. approved a $0.34 per share cash dividend on July 30, 2025. A copy of the press release is attached hereto as Exhibit 99.1 . This is an increase of $0.01, or 3.03 percent, compared to a cash dividend of $0.33 per share declared in the same period in the prior year. The annualized yield using the July 29, 2025, closing price of $37.63 is 3.61 percent. The dividend is payable August 28, 2025, to shareholders of record on August 14, 2025.

of this Report on Form 8-K, including Exhibit 99.1, is being furnished and shall not be deemed "filed" for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall such information be deemed incorporated by reference in any filing under the Securities Exchange Act of 1933, as amended (the “Securities Act”), or the Exchange Act, except as shall be expressly set forth by specific reference…

Chief Accounting Officer — Melanie A. Lazzari: The filing discloses the internal promotion of a long-serving controller to the role of Executive Vice President and Chief Accounting Officer.

Other Events. On May 13, 2025, the Board of Directors of S&T Bancorp, Inc. authorized an extension of its $50 million share repurchase plan, which was set to expires on May 30, 2025. The new repurchase authorization will expire July 31, 2026 and permits S&T to repurchase shares of S&T's common stock from time to time through a combination of open market or privately negotiated repurchases up to the authorized $50 million aggregate value of S&T's common stock. The specific timing, price and qu…

Other Events. The Board of Directors of S&T Bancorp, Inc. approved a $0.34 per share cash dividend on April 30, 2025. A copy of the press release is attached hereto as Exhibit 99.1 . This is an increase of $0.01, or 3.03 percent, compared to a cash dividend of $0.33 per share declared in the same period in the prior year. The annualized yield using the April 29, 2025 closing price of $37.17 is 3.66 percent. The dividend is payable May 29, 2025 to shareholders of record on May 15, 2025.

of this Report on Form 8-K, including Exhibit 99.1, is being furnished and shall not be deemed "filed" for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall such information be deemed incorporated by reference in any filing under the Securities Exchange Act of 1933, as amended (the “Securities Act”), or the Exchange Act, except as shall be expressly set forth by specific reference…

of this Report on Form 8-K, including Exhibit 99.1 , is being furnished and shall not be deemed "filed" for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall such information be deemed incorporated by reference in any filing under the Securities Exchange Act of 1933, as amended (the “Securities Act”), or the Exchange Act, except as shall be expressly set forth by specific reference…

Other Events. The Board of Directors of S&T ("Board") approved a $0.34 per share cash dividend on January 29, 2025. A copy of the press release is attached hereto as Exhibit 99.4 . This is an increase of $0.01, or 3.03 percent, compared to a cash dividend of $0.33 in the same period in the prior year. The annualized yield using the January 28, 2025 closing price of $38.16 is 3.56 percent. The dividend is payable February 27, 2025 to shareholders of record on February 13, 2025. The information…

Other Events. The Board of Directors of S&T Bancorp, Inc. approved a $0.34 per share cash dividend on October 23, 2024. A copy of the press release is attached hereto as Exhibit 99.1 . This is an increase of $0.01, or 3.03 percent, compared to a cash dividend of $0.33 per share declared in the same period in the prior year. The annualized yield using the October 22, 2024 closing price of $38.75 is 3.51 percent. The dividend is payable November 21, 2024 to shareholders of record on November 7,…

of this Report on Form 8-K, including Exhibit 99.1, is being furnished and shall not be deemed "filed" for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall such information be deemed incorporated by reference in any filing under the Securities Exchange Act of 1933, as amended (the “Securities Act”), or the Exchange Act, except as shall be expressly set forth by specific reference…

Director — Peter G. Gurt: The filing discloses the appointment of a new independent director to the board, which is a routine governance action and not a departure of a senior executive.