2026 Thousand Islands Triathlon & Runs

The annual Thousand Islands Triathlon & Runs is back at Centeen Park in Brockville on Sunday, August 9th.

The event combines swimming, biking, and running in a scenic and challenging race, including a run through Brockville’s historic railway tunnel. The event is open to everyone, no matter their skill level, with different lengths, giving participants flexible options.

The Online Registration Deadline (if not already sold out) is Thursday, August 6th at 6 pm. Sign up before this date to have your name included on the Athlete Wall. After this date, registration is subject to availability. Some of their races sell out, so make sure to sign up early!

The transition area is in Centeen Park for the fourth year.

The Brockville Railway Tunnel is closed to the public from 8:00 am to 11:00 am for the triathlon.

Water Street East from Park Street and Ford Street and Ford Street from Water Street to King Street will be used for the bike portion of the triathlon and will be closed to traffic between 6:00 am to 11:00 am.

King Street East from Park Street to North Augusta Road will also be used for the bike portions of the triathlon and will be closed to traffic from 8:00 am to 11:30 am.

The event will feature the Olympic Triathlon, Olympic Triathlon Relay, Sprint Duathlon, Olympic Duathlon, Olympic Swim Cycle, 5K Run, 10K Run, Sprint Triathlon, Sprint Triathlon Relay and Try a Tri.

Everything gets underway at 8:00 am with the Olympic Triathlon and Olympic Swim Cycle. The Sprint Duathlon is at 8:30 am, while the 10k run starts at 9:00 am followed by the Sprint Triathlon starting at 9:15 am. The 5K run begins at 9:30 am followed by the start of the Try a Tri at 10:00 am.

Spectators are encouraged to come out and cheer on the athletes, or plan if you’re travelling through the area during these times.

For more information, please visit: https://www.somersault.ca/event/thousand-islands