There are 48 half marathons in Illinois scheduled for 2026. The next is the Haunted Halloween Half Marathon & 5km in Chicago on October 25. Illinois half marathons run primarily October through September.

Dam Site Run

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

Iceman Series 2026-27

Sat, Dec 12 · Springfield, IL Springfield
Iceman Half Marathon, 10K & 5KIceman Series 15K, 10K or 5K - 1/9 at 9amIceman Series 18K, 10K or 5K - 1/23 at 9am +4

MIDWEST OCR

Sat, Sep 18 · Marseilles, IL Marseilles
9:45am - 3+ Mile Fun Run10:45am - 3+ Mile Fun Run9:45am - 3+ Mile RUCK +35