S&T BANCORP INC

(Former name or former address, if changed since last report.)

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Securities registered pursuant to Section 12(b) of the Act:

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.☐

Item 5.02 Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers.

(d) On October 29, 2025, the Board of Directors (the "Board") of S&T Bancorp, Inc. ("S&T") appointed Stephanie Nycum Doliveira to serve on the Board, effective immediately. Ms. Doliveira was also appointed as a director of S&T Bank, effective immediately. The Board determined that Ms. Doliveira is independent in accordance with the director independence standards established by Nasdaq. The committees on which Ms. Doliveira will serve have not been determined. She will be eligible to receive compensation for her Board service according to the recommendations of the Nominating and Corporate Governance Committee of the Board and the determination of the Board with respect to compensation for all non-employee directors. For her service on the board from October 29, 2025 through the next annual shareholder meeting in 2026, she will receive a prorated cash retainer of $40,833 and an equity award in the form of restricted stock units valued at $29,167.

Ms. Doliveira has served as the Executive Vice President of People & Culture at Sheetz, Inc, since January 2023. Prior to her current role, she served in many leadership roles within the organization, including Vice President of Human Resources, Interim Manager of Brand Strategy and Manager of Internal Communications. Preceding the start of her career with Sheetz, Inc. in 2003, Ms. Doliveira was a practicing labor and employment attorney with Andrews, Wagner & Beard in Altoona, Pennsylvania. Ms. Doliveira holds a juris doctorate from Widener University Commonwealth Law School and a bachelor’s degree in labor and industrial relations from Pennsylvania State University.

There are no arrangements or understandings between Ms. Doliveira and any other person pursuant to which Ms. Doliveira was appointed to the Board. There are no other transactions to which S&T is a party in which Ms. Doliveira has an interest that would require disclosure under Item 404(a) of Securities and Exchange Commission Regulation S-K. S&T issued a press release on October 29, 2025 regarding the appointment of Ms. Doliveira to the Board. A copy of the press release is furnished herewith as Exhibit 99.1.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits.