There are 52 half marathons in Illinois scheduled for 2026. The next is the Naperville Trails Half Marathon & 10K in Wheaton on September 5. Illinois half marathons run primarily September through July.

Trail Mix

Sun, Oct 4 · Rockford, IL Rockford
Half-Mix DuathlonSport Mountain BikeTeam Relay +2

Dam Site Run

Sun, Nov 1 · LeRoy, IL LeRoy
Dam Site Half MarathonCharity Entry (Timed Half Marathon, but No Medal/Swag)