EXHIBIT 99.1 Noninterest expense increased $3.5 million, or 9.4%, to $40.6 million for the three months ended March 31, 2026, compared to $37.1 million for the same period in 2025. On a linked quarter basis, noninterest expense increased by $3.1 million or 8.3%, compared to the three months ended December 31, 2025. The increase for both periods was primarily due to increases in SOUTHSIDE BANCSHARES, INC. ANNOUNCES FINANCIAL RESULTS FOR THE FIRST QUARTER ENDED MARCH 31, 2026 Tyler, Texas (April 30, 2026) Sou ...