Exhibit 99.1 Wintrust Financial Corporation 9700 W. Higgins Road, Suite 800, Rosemont, Illinois 60018 News Release FOR IMMEDIATE RELEASE April 17, 2024 FOR MORE INFORMATION CONTACT: Timothy S. Crane, President & Chief Executive Officer David A. Dykstra, Vice Chairman & Chief Operating Officer (847) 939-9000 Web site address: www.wintrust.com Wintrust Financial Corporation Reports Record First Quarter 2024 Net Income ROSEMONT, ILLINOIS – Wintrust Financial Corporation (“Wintrust”, “the Company”, “we” or “our ...