How many races are there in May 2027 in Ontario?

15 with a confirmed date, and the biggest group is 5K races with 10. The busiest single day is Saturday, May 15, 2027, with 3 races. Recompiled nightly from the organizers' own calendars, so the number moves as races are announced.

When should I register for a May race?

Most Canadian races take entries until race week — what expires first is the price tier, not the spot. Check the fee window on the race's page before you wait.

No. Every listing links straight to the organizer's own registration page. RaceFinder never takes signups or a cut.

Races in May 2027 in Ontario

15 races with a confirmed date in May 2027 across Ontario — the biggest group is 5K races (10). The busiest day is Saturday, May 15, 2027 with 3 races. Every listing links to the organizer's official registration page.

← April June →May across Canada

The big ones in May

Multi-distance race weekends — the ones worth planning around.

Sunday, May 2, 2027
Georgina Spring Fling 2027
Georgina, ON · Road · 42km / 21km / 10km / 5km · from $76
Saturday, May 8, 2027
'Goode Run 2027
Ottawa, ON · Road · 7km / 5km / 2km · from $18
Saturday, May 8, 2027
Shoppers Drug Mart® Run for Women - Waterloo 2027
Kitchener, ON · Road · 10km / 5km / 1km
Saturday, May 15, 2027
Horseshoe Valley Hustle
Barrie, ON · Trail · 10km / 5km / 1km · from $19
Saturday, May 22, 2027
Shoppers Drug Mart® Run for Women - Oakville 2027
Oakville, ON · Road · 10km / 5km / 1km
Sunday, May 23, 2027
Shoppers Drug Mart® Run for Women - Markham 2027
Markham, ON · Road · 10km / 5km / 1km
Saturday, May 29, 2027
Tamarack Ottawa Race Weekend
Ottawa, ON · Road · 42.2km / 21.1km / 10km / 5km
Saturday, May 29, 2027
Sulphur Springs Trail Race
Ancaster, ON · Trail · 100mi / 100km / 50mi / 20km

What May is made of

5K races · 10 10K races · 10 Half marathons · 3 Marathons · 2 Ultramarathons · 1

Where they are

Ottawa · 2 Ancaster · 1 Barrie · 1 Brighton · 1 Kitchener · 1 Markham · 1 Oakville · 1 Perth · 1

Every race in May

When

Confirmed dates only

15 races listed

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.

Other months

November 2026 December 2026 January 2027 February 2027 March 2027 April 2027

Races in May 2027 — FAQ

How many races are there in May 2027 in Ontario?: 15 with a confirmed date, and the biggest group is 5K races with 10. The busiest single day is Saturday, May 15, 2027, with 3 races. Recompiled nightly from the organizers' own calendars, so the number moves as races are announced.
When should I register for a May race?: Most Canadian races take entries until race week — what expires first is the price tier, not the spot. Check the fee window on the race's page before you wait.
Do I sign up here?: No. Every listing links straight to the organizer's own registration page. RaceFinder never takes signups or a cut.

Planning further out? Build a season, see when race season peaks in Canada, or check which entry fees go up next.