Illinois
Illinois Triathlon Calendar 2026-2027
Monthly updates for Illinois
Get new running races (and updates) in your inbox every month.
Explore the best triathlons in Illinois for 2026-2027! Our updated list features 22 exciting races across the region. Find your next race in Illinois below and join the running community at these great events!
June 2026
Triathlon day in Tremont Illinois on June 20, 2026 with sprint and mini distances, relays, and double-event options. Awards cover age groups and special categories and entry fees vary by event.
July 2026
A multi-discipline race day at Paulus Park in Lake Zurich on July 12, 2026 featuring Olympic and Sprint triathlons plus duathlon and aquabike options, with individual and relay entry categories.
MTC Zilla Tri in Columbia, Illinois features a Sprint, an expanded Youth Short Sprint, and a clinic with a course preview. Pool swims, on-road bike courses with one hill and a railroad crossing, and neighborhood runs make up the event.
Crystal Lake Aquathon returns July 19, 2026 at Three Oaks Recreation Area with timed swim and run events across multiple distances, a kids race, and an adaptive swim. Proceeds benefit Girls on the Run of Northwest Illinois.
A pool-based triathlon in Champaign, IL featuring a 400 yard swim, 10 mile bike and 5K run. Resident and non-resident divisions have different fees and registration runs in early to mid 2026.
A youth triathlon at Northwestern Medicine Delnor Fitness and Health Center featuring pool swims and trail runs for ages 6 to 17, chip timing, finisher medals, and a required USAT license.
Experience a flat and fast course at Lake Springfield with sprint, olympic, and half distance options. Enjoy a calm lake swim followed by a shaded run and scenic bike path in the heart of Illinois.
Wauconda Triathlons offers adult Olympic and sprint races plus a kids race in Wauconda. It is part of the Lake County sprint series and provides course maps, elevation profiles, transition maps, and past race results.
August 2026
An annual multi sport event at Centennial Beach in downtown Naperville, the 2026 Naperville Sprint Triathlon features sprint, duathlon, aquabike, and a kids triathlon with defined swim, bike, and run distances.
A sprint triathlon in Olney Illinois featuring a 200 meter swim, a 14.2 mile bike ride, and a 3.1 mile run. Categories include age group, team, and Zeus/Xena divisions with awards for top finishers.
Sage City Triathlon in Monticello offers sprint and mini triathlon distances, a shallow pool, age-group and overall awards, and post-race food. Registration opens March 1 and the event is not USAT sanctioned.
A short-course triathlon on August 15, 2026 in O'Fallon, IL featuring a 150 m pool swim, 10 mile bike through rolling hills, and a 2 mile flat run. Post-race breakfast is available and proceeds support a memorial foundation.
Supertri Chicago is a multi-distance triathlon across Lake Michigan and Chicago streets on August 22-23, 2026. Races include SuperSprint, Sprint, Olympic, Triple Challenge and kids events with individual and relay options.
A community race day in Morrison, Illinois with a 5K out-and-back, a duathlon including a 21-mile bike, children's fun runs, and a color run; courses start at Morrison High School and include rolling hills and on-course water stops.
Experience a beach start at Illinois largest man made lake followed by a flat bike course and a finish over the dam spillway. This event offers individual and relay options across triathlon duathlon and aquabike distances.
A sprint triathlon on the University of Illinois campus with a 300 meter pool swim in the ARC outdoor 50 meter pool, a 14 mile bike on a flat course, and a 5k run. Packet pickup occurs the day before and on race morning.
October 2026
A draft legal sprint triathlon for NCAA collegiate women at Clinton Lake SRA featuring a 750 m swim, 12 mile bike and 3.2 mile run, organized in two waves with segment time limits.
A short course triathlon at the Mattoon Area Family YMCA featuring a 275 yard pool swim, a 12 mile bike and a 3.1 mile run. Helmets are required and headphones are not allowed on the bike.
November 2026
Indoor triathlon at Oak Brook Park District on November 22, 2026 featuring rowing, stationary cycling, and a track run. Open to ages 12 and up with heats assigned by age and gender; registration runs September 1 to October 1 for $20.