Exhibit 99.1 KIRBY CORPORATION Contact: Kurt Niemietz 713-435-1077 FOR IMMEDIATE RELEASE KIRBY CORPORATION ANNOUNCES 2025 SECOND QUARTER RESULTS HOUSTON, July 31, 2025 – Kirby Corporation ("Kirby") (NYSE: KEX) today announced net earnings attributable to Kirby for the second quarter ended June 30, 2025, of $94.3 million or$1.67 per share, compared with earnings of $83.9 million, or$1.43 per share for the 2024 second quarter. Consolidated revenues for the 2025 second quarter were $855.5 million compared wi ...