Marathons in Ontario

Ontario is home to 3 marathons in our database in Canada, spread across cities including Hamilton, Ottawa, and Toronto. Toronto Waterfront Marathon is the largest race in the lineup, typically drawing around 14,000 finishers, while the full spread offers everything from fast urban courses to scenic regional events. Browse the races below for course maps, elevation profiles, typical weather, and practical race-day detail to help you choose your next start line. Plan by month on our marathon calendar or filter by country and region.

Ottawa, Ontario, Canada🇨🇦

Ottawa Marathon

The Ottawa Marathon draws approximately 3,500 finishers on an urban road in Ottawa, Canada. The course starts and finishes at Ottawa City Hall. The route crosses the Ottawa River into Gatineau, passes Parliament Hill, and follows the Rideau Canal. Mostly flat with a climb on the Alexandra Bridge.

Next race: Sunday, 23 May 2027

Hamilton, Ontario, Canada🇨🇦

Road2Hope Hamilton Marathon

The Road2Hope Hamilton Marathon draws approximately 1,500 finishers each May on an urban road in Hamilton, Canada. Ontario's premier spring marathon links Hamilton's escarpment city with a Boston-qualifier certified course. The loop passes the Niagara Escarpment, Hamilton waterfront, and the city's industrial heritage corridors. The route is net downhill overall.

Next race: Sunday, 2 May 2027

Toronto, Ontario, Canada🇨🇦

Toronto Waterfront Marathon

The Toronto Waterfront Marathon is one of the world's largest marathons, drawing approximately 14k finishers on an urban road in Toronto, Canada. The course starts and finishes at Nathan Phillips Square. The route follows the Lake Ontario waterfront through the Beaches, High Park, and downtown Toronto. Mostly flat with minor rises leaving the lakeshore.

Next race: Sunday, 18 October 2026

Nearby Marathons

Other races closest to Ontario.

Buffalo, New York, United States🇺🇸· 145 km away

Buffalo Marathon

The Buffalo Marathon draws approximately 1,209 finishers each May on an urban road in Buffalo, United States. Western New York's signature Memorial Day marathon combines a flat course with strong local crowd support. The route passes Delaware Park, waterfront stretches along Lake Erie, and Buffalo neighborhoods on a flat urban loop. The course is very flat throughout.

Next race: Sunday, 2 May 2027

Erie, Pennsylvania, United States🇺🇸· 264 km away

Erie Marathon

The Erie Marathon draws approximately 1,300 finishers each September on a lakeside loop road in Erie, United States. Running almost entirely inside a state park gives it an unusually calm race-day feel for a fast marathon. The loop passes Lake Erie shoreline, wooded park roads, and wide open lake views with almost no climbing. The course is very flat throughout.

Next race: Sunday, 6 September 2026

Scranton, Pennsylvania, United States🇺🇸· 371 km away

Steamtown Marathon

The Steamtown Marathon draws approximately 1,500 finishers each October on a net-downhill point-to-point from Forest City to downtown Scranton, Pennsylvania. The course descends through the Pocono foothills and Lackawanna Valley on scenic country roads with autumn foliage. October's peak Pennsylvania colour and the fast descent make it a popular Boston-qualifier in the Anthracite Coal Region.

Next race: Sunday, 11 October 2026

Cleveland, Ohio, United States🇺🇸· 401 km away

Cleveland Marathon

The Cleveland Marathon draws approximately 4,500 finishers on an urban road in Cleveland, United States. The course starts and finishes in downtown Cleveland. The route crosses the Hope Memorial Bridge, passes Rock and Roll Hall of Fame, and follows the Lake Erie shoreline. Hilly with climbs on the Hope Memorial Bridge and through Ohio City.

Next race: Sunday, 16 May 2027

Montreal, Quebec, Canada🇨🇦· 403 km away

Montreal Marathon

The Montreal Marathon is one of the world's largest marathons, drawing approximately 13k finishers on an urban road in Montreal, Canada. The course starts and finishes in Old Montreal. The route crosses the Jacques Cartier Bridge, passes Mount Royal Park, and follows the St Lawrence riverfront. Rolling terrain with a notable climb on the Jacques Cartier Bridge.

Next race: Sunday, 11 October 2026