Triathlons & duathlons in Ontario

Triathlons & duathlons across Ontario: 16 with a confirmed date (41 more are waiting on a date). Welland, Sarnia and Toronto have the most. Next up: Gravenhurst - Sat June 12 and Sun June 13 on June 13, 2027.

Updated daily — every listing links to the organizer's official registration page.

5K races 10K races Half marathons Marathons Ultramarathons Trail races

When

Confirmed dates only

57 races listed

Date to be announced
Superior Triathlon #1Date TBA
Thunder Bay, ON · Triathlon / duathlon · 8km
Date to be announced
Superior Indoor Triathlon #2Date TBA
Thunder Bay, ON · Triathlon / duathlon · 8km
Date to be announced
TRi KiDS Triathlon Series LONDON, ONDate TBA
London, ON · Triathlon / duathlon
Date to be announced
Tinman TriathlonDate TBA
Elmira, ON · Triathlon / duathlon · 1.6km
Date to be announced
TRi KiDS Triathlon Series BURLINGTON, ONDate TBA
Burlington, ON · Triathlon / duathlon
Date to be announced
Subaru Triathlon Series - MiltonDate TBA
Milton, ON · Triathlon / duathlon
Sunday, June 13, 2027
Gravenhurst - Sat June 12 and Sun June 13
Gravenhurst, ON · Triathlon / duathlon · 51km / 25km · from 129
Date to be announced
Oak Ridges Moraine Adventure RelayDate TBA
Gores Landing, ON · Triathlon / duathlon · 160km / 80km
Date to be announced
MultiSport Canada Gravenhurst TriathlonDate TBA
Gravenhurst, ON · Triathlon / duathlon
Date to be announced
K'Town Kids DuathlonDate TBA
Kingston, ON · Triathlon / duathlon · 9.2km

New races in Ontario, once a month

Newly listed races, and the registrations closing in the next three weeks. One email a month. Every subscriber is in the monthly $25 gift-card draw, held on the 1st. One click to leave.

Triathlons & duathlons in Ontario — FAQ

How many triathlons & duathlons are there in Ontario in 2026?: Triathlons & duathlons listed for Ontario right now: 16 with a confirmed date, plus 41 that ran last season and haven't announced their next one. The list refreshes nightly as organizers announce new dates.
What is the next one in Ontario?: Gravenhurst - Sat June 12 and Sun June 13 in Gravenhurst on June 13, 2027.
Which Ontario cities host the most triathlons & duathlons?: Welland (2), Sarnia (2), Toronto (2).