第一金融银行美股招股说明书(2025-11-07版)

6.375%Fixed-to-FloatingRate Subordinated Notes due 2035 We are offering $300,000,000 aggregate principal amount of 6.375 %Fixed-to-FloatingRate Subordinated Notes due 2035 (the “subordinated notes”). The subordinatednotes will mature on December1, 2035. From and including the date of original issuance to, but excluding, December1, 2030, or the date of early redemption, thesubordinated notes will bear interest at a fixed rate of 6.375% per annum, payable semiannually in arrears on June1 and December1 of each year, commencing onJune1, 2026. From and including December1, 2030, to, but excluding the maturity date or the date of early redemption, the subordinated notes will bear interest at afloating rate per annum equal to a benchmark rate (which is expected to be Three-Month Term SOFR (as defined herein)) plus a spread of 300 basis points, payablequarterly in arrears on March1, June1, September1 and December1 of each year, commencing on March1, 2031. Notwithstanding the foregoing, in the event thatbenchmark rate is less than zero, then the benchmark rate shall be deemed to be zero. We may, at our option, redeem the subordinated notes (i)in whole or in part beginning with the interest payment date of December1, 2030, and on any interest paymentdate thereafter or (ii)in whole but not in part upon the occurrence of a “Tax Event,” a “Tier 2 Capital Event” or First Financial Bancorp. becoming required to register asan investment company pursuant to the Investment Company Act of 1940, as amended (the “1940 Act”). The redemption price for any redemption is 100% of theprincipal amount of the subordinated notes, plus accrued and unpaid interest thereon to, but excluding, the date of redemption. Any early redemption of the subordinatednotes will be subject to the receipt of the approval of the Board of Governors of the Federal Reserve System to the extent then required under applicable laws orregulations, including capital regulations. There is no sinking fund for the subordinated notes. The subordinated notes will rank junior to all of our existing and future senior indebtedness. In addition, thesubordinated notes will be effectively subordinated to all of our secured indebtedness to the extent of the value of the assets securing such indebtedness. The subordinatednotes will be structurally subordinated to all of the existing and future liabilities and obligations of our subsidiaries, including the deposit liabilities and claims of othercreditors of our bank subsidiary, First Financial Bank. The subordinated notes will be equal in right of payment with any of our existing and future subordinatedindebtedness, including our 5.25% subordinated notes due 2030. The subordinated notes will be obligations of First Financial Bancorp. only and will not be obligationsof, and will not be guaranteed by, any of our subsidiaries. For a more detailed description of the subordinated notes, see “Description of Subordinated Notes.” The subordinated notes will not be listed on any national securities exchange or quoted on a quotation system. Currently, there is no public market for the subordinatednotes. Public Offering Price(1) (2)We will also reimburse the underwriters for certain expenses incurred in this offering. See “Underwriting” in this prospectus supplement for details. The underwriters expect to deliver the subordinated notes to investors in book-entry only form on or about November10, 2025, which is the second business dayfollowing the date of pricing the subordinated notes (such settlement being referred to as “T+2”). See “Underwriting” beginning on pageS-44of this prospectussupplement for details. Investing in the subordinated notes involves certain risks, including that the interest rate on the subordinated notes during the floating rateperiod may be determined based on a rate other thanThree-MonthTerm SOFR. Please read “Risk Factors” beginning on pageS-7of thisprospectus supplement, on page 5 of the accompanying prospectus, beginning on page 14 of our Annual Report on Form 10-K for the yearended December31, 2024, which Annual Report is incorporated by reference herein, and carefully consider that information before investing inthe subordinated notes. The subordinated notes are not savings accounts, deposits or other obligations of First Financial Bank or any nonbank subsidiaries. The subordinated notes arenot insured or guaranteed by the Federal Deposit Insurance Corporation (the “FDIC”), or any other government agency or public or private insurer. Neitherthe Securities and Exchange Commission, any state securities commission, the FDIC, the Board of Governors of the Federal Reserve System nor any otherregulatory body has approved or disapproved of these securities or passed upon the adequacy or accuracy of this prospectus supplement or the accompanyingprospectus. Any representation to the contrary is a criminal offense. Joint Book-Running Managers Keefe,Bruyette&WoodsAStifelCompany JanneyMontgomeryScott The da