EXHIBIT 99.1 OCTOBER 31, 2025 NEWS FOR IMMEDIATE RELEASE CONTACT: ERIC J. DOSCH, CFO 985.375.0308 First Guaranty Bancshares, Inc. Announces Third Quarter 2025 Financial Results Hammond, Louisiana, October 31, 2025 – First Guaranty Bancshares, Inc. ("First Guaranty") (NASDAQ: FGBI), the holding company for First Guaranty Bank, announced its unaudited financial results for the third quarter and nine months ending September 30, 2025. Financial Highlights for the third quarter and nine months ended September 30 ...