First Commonwealth Financial Corporation

Item 5.03 Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year On July 28, 2026, the Board of Directors of First Commonwealth Financial Corporation (the “Company”), approved the following amendments to the Company’s By-Laws: • Section 2.1 was amended to incorporate requirements of the Pennsylvania Business Corporation Law for meetings of shareholders that are held solely by means of the Internet or other electronic communications technology. • Section 2.5(a)(3), which sets forth disclosure requirements for advance notice of nominations or other business to be brought before a meeting by shareholders, was amended to require that shareholders wishing to nominate directors solicit proxies from holders representing at least 67% of the voting power of shares entitled to vote on the election of directors, in compliance with Rule 14a-19 under the Exchange Act. • Section 5.7, which addresses vacancies on the Board of Directors, was amended to remove a reference to classes of directors and confirm that a Director appointed to fill a vacancy serves until the next annual meeting of shareholders and until his or her successor is elected and qualified. • Article 10 was amended to replace “Chairman” with “Chair” throughout. The text of the Amended and Restated By-Laws is filed with this Report as Exhibit 3.1, and the descriptions in this Report are qualified in their entirety by reference to that exhibit.