Exhibit 99.1 News Release Trustmark Corporation Announces Third Quarter 2025 Financial Results Performance Reflects Continued Loan and Deposit Growth, Stable Credit Quality, Expanded Revenue and Strong Profitability Metrics JACKSON, Miss. – October 28, 2025 – Trustmark Corporation (NASDAQGS:TRMK) reported net income of $56.8 million in the third quarter of 2025, representing diluted earnings per share of$0.94. Trustmark's performance during the third quarter produced a return on average tangible equity of ...