Marathons in Ontario
31 upcoming marathons across Ontario, with the deepest fields in Toronto, Niagara Falls, Ottawa. Next up: Georgina Marathon & Half-Marathon on September 13, 2026.
Updated daily — every listing links to the organizer's official registration page.
31 races listed
Save the Bees Virtual RunDate TBA
Toronto, ON · Road running · 1mi / 5km / 10km / 21km
Georgina Marathon & Half-Marathon
Jacksons Point, ON · Road running · 42km / 10km / 21km / 5km
Monster of Mazinaw Trail Race 2026
Cloyne, ON · Trail · 10km / 30km / 43km
2026 Muskoka Marathon
Bracebridge, ON · Road running · 42km / 21km / 10km / 5km
The County Marathon 2026
Prince Edward, ON · Road running · 21km / 42km / 5km / 1km
The Maple Leaf March -- La Marche Maple Leaf
Ottawa, ON · Road running · 5km / 10km / 21km / 42km
2026 TCS Toronto Waterfront Marathon
Toronto, ON · Road running · 5km / 42km / 21km
2026 Women's Training Program
Toronto, ON · Road running · 42km / 21km
U.S. & International Registrants, Niagara Falls 10k, Half & Marathon 2026
Niagara Falls, ON · Road running · 42km / 21km / 10km
Niagara Falls 10k, Half & Marathon 2026
Niagara Falls, ON · Road running · 42km / 21km / 10km
Niagara Falls 5k, 10k, Half & MarathonDate TBA
Niagara Falls, ON · Road running · 42km / 21km / 10km / 5km
U.S. & International Registrants, Niagara Falls 5k, 10k, Half & MarathonDate TBA
Niagara Falls, ON · Road running · 42km / 21km / 10km / 5km
2026 Hamilton Marathon Road2Hope
Hamilton, ON · Road running · 5km / 1km / 10km / 21km
Nemo Memorial Run - Run for the Heroes.
Toronto, ON · Road running · 5km / 10km / 21km / 42km
Run to End Child Hunger
Toronto, ON · Road running · 1mi / 5km / 10km / 21km
RK QA Deeplink Races
London, ON · Road running · 100m / 1km / 42km
2027 Beneva Mississauga Marathon
Mississauga, ON · Road running · 42km / 21km / 10km / 5km
St Lawrence MarathonDate TBA
Cornwall, ON · Road running · 42km / 21km / 10km / 5km
Georgina Spring Fling 2027
Georgina, ON · Road running · 42km / 21km / 10km / 5km
Toronto MarathonDate TBA
Toronto, ON · Road running · 42km / 21km / 10km / 5km
SudburyROCKSDate TBA
Greater Sudbury, ON · Road running · 42km / 21km / 10km / 5km
Marathon for mental health and addictionDate TBA
Mount Forest, ON · Road running · 42km
Niagara UltraDate TBA
Niagara-on-the-Lake, ON · Trail · 80km / 50km / 42km / 21km
Canada Day Virtual Walk and RunDate TBA
Toronto, ON · Road running · 1mi / 5km / 8km / 10km
Scotiabank Toronto Waterfront Marathon Virtual RaceDate TBA
Toronto, ON · Road running · 42km / 21km / 10km / 5km
Scotiabank Toronto Waterfront MarathonDate TBA
Toronto, ON · Road running · 42km / 1km / 5km / 10km
Tamarack Ottawa Virtual Race WeekendDate TBA
Ottawa, ON · Trail · 42km / 2km / 5km / 10km
Scotiabank Toronto Waterfront Marathon - International RegistrationDate TBA
Toronto, ON · Road running · 42km / 21km / 10km / 5km
RUN12Date TBA
Virtual, ON · Road running · 42km
Niagara Falls 5k, 10k, Half & International MarathonDate TBA
Niagara Falls, ON · Road running · 42km / 21km / 10km / 5km
U.S. & International Registrants, Niagara Falls 5k, 10k, Half & International MarathonDate TBA
Niagara Falls, ON · Road running · 42km / 21km / 10km / 5km