EXHIBIT 99.1 SOUTHSIDE BANCSHARES, INC. ANNOUNCES FINANCIAL RESULTS FOR THE SECOND QUARTER ENDED JUNE 30, 2025 Tyler, Texas (July 25, 2025) Southside Bancshares, Inc. ("Southside" or the "Company") (NYSE: SBSI) today reported its financial results for the quarter ended June 30, 2025. Southside reported net income of $21.8 million for the three months ended June 30, 2025, a decrease of$2.9 million, or 11.6%, compared to $24.7 million for the same period in 2024. Earnings per diluted common share decreased$ ...