Exhibit 99.1 NEWS RELEASE FOR IMMEDIATE RELEASE GATX CORPORATION REPORTS 2026 SECOND-QUARTER RESULTS CHICAGO, July 30, 2026—GATX Corporation (NYSE: GATX) today reported 2026 second-quarter net income attributable to GATX of $103.4 million, or $2.84 per diluted share, compared to net income attributable to GATX of $75.5 million, or $2.06 per diluted share, in the second quarter of 2025. Net income attributable to GATX for the first six months of 2026 was $188.9 million, or $5.19 per diluted share, compared t ...