Illinois has a growing Triathlon scene. With miles of rolling hills, challenging forest trails and an abundance of rivers and lakes it has the perfect ingredients for beautiful and challenging racing.

Whether you’re a seasoned triathlete wanting to test yourself over a 70.3/half distance or ironman/full distance race or a beginner to the sport looking to try out a Super Sprint distance, Sprint distance or Olympic triathlon you’re in the right place. Whatever type of race you fancy you’ll find it in the Prairie state. You can choose your distance of choice across a diverse range of terrains from the city routes of Chicago to the beaches of Lake Michigan.

If its big crowds and big city racing you’re after then why not try the Chicago Triathlon, one of the largest triathlons in the world. If you fancy dipping your toe on a smaller scale how about a local tri like the Sage City Triathlon?

Whatever your goal, you’ll find the most comprehensive list of Triathlons in Illinois at findarace.

Check out our exhaustive 2025 - 2026 Illinois Triathlon calendar list below, and use our month, distance and terrain filters to find your next challenge.