Illinois Triathlon Calendar 2025-2026

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Explore the best triathlons in Illinois for 2025-2026! Our updated list features 307 exciting races across the region. Find your next race in Illinois below and join the running community at these great events!

October 2026
Oct
3-4
Sa - Su

The Hennepin Hundred

Trail Run 50 km 50 mi 100 mi
Oct
4
Sunday

Chicago 10K

10 km
Oct
4
Sunday

Bronzeville 5K

5 km
Oct
10-11
Sa - Su

Arrowhead Endurance Run

Backyard Ultra 3 hr 6 hr 12 hr 24 hr
Oct
16-17
Fr - Sa

Shake Your Trail Feather Trail Run

Trail Run 5 km 8 mi ... 50 km 100 km
Oct
17
Saturday

Saw Wee Kee - Fall Trail Run

Trail Run
Oct
26-27
Mo - Tu

Hot Cider Hustle - Wheaton

5 km 8 mi
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