Ottawa Marathon 2027: dates, course and distances for the Tamarack Ottawa Race Weekend

The short version: the Tamarack Ottawa Race Weekend 2027 runs on Saturday, May 29 and Sunday, May 30, 2027. The marathon (42.2 km) starts Sunday at 7:00 a.m., the half marathon (21.1 km) at 9:00 a.m., and every race starts at Ottawa City Hall, 110 Laurier Avenue West. Registration for 2027 is open on the official site, runottawa.ca.

We first ran Ottawa together in the spring of 2024. Stéphane went back in 2025, and in 2026 it’s where we took our very first group. So we know the place. This is the guide we wish we’d had before signing up the first time — and everything in it comes straight from the organizer’s official pages at Run Ottawa.

Race weekend dates for 2027

The weekend splits neatly in two: short races on Saturday, the long ones on Sunday morning.

Saturday, May 29, 2027

1:00 p.m. — Ottawa Kids Marathon (1.2 km, ages 5 to 12)
3:00 p.m. — Ottawa 2K
4:00 p.m. — Ottawa 5K
6:00 p.m. — Ottawa 10K presented by Otto’s Ottawa

Sunday, May 30, 2027

7:00 a.m. — Tamarack Ottawa International Marathon
9:00 a.m. — Ottawa Half Marathon presented by Desjardins

All times are Eastern, and every race leaves from the same spot: Ottawa City Hall, 110 Laurier Avenue West, right downtown.

Which distance is right for you?

The marathon (42.2 km). The headline event, and one of Canada’s best-known marathons for over 50 years. It carries a World Athletics Elite Label, runs on a certified course and is a Boston Marathon qualifier. It’s open to runners 18 and over, with a field capped at 6,000.

The half marathon (21.1 km). The weekend’s most popular race — and the fastest to sell out. Run Ottawa calls the course fast and relatively flat, which makes it a strong pick for a personal best or a first crack at the distance. Open from age 16, with room for 12,000 runners.

The 10K. Saturday evening, and it doubles as the Canadian 10K Championships, so you’ll be sharing the road with a wave of pro runners. Open from age 14.

The 5K and 2K. The 5K is open from age 5. The 2K is the family race of the weekend, and the only one where strollers are allowed.

Multi-race challenges. If one race isn’t enough:

Ottawa 17K Challenge — 2K + 5K + 10K, all on Saturday;
Ottawa 36.1K Challenge — 5K + 10K on Saturday, then the half marathon on Sunday;
Ottawa 59.2K Challenge — 2K + 5K + 10K on Saturday, then the marathon on Sunday.

Each challenge comes with a medal for every race plus a dedicated challenge medal.

The course

Run Ottawa publishes an interactive course map covering every race, with road closures and elevation profiles; a button at the bottom switches between Saturday and Sunday routes. The organizer notes that routes may be adjusted slightly at the last minute, so check the map again in the days before the race.

What the official pages say about the terrain:

the 10K follows the Rideau Canal, a UNESCO World Heritage Site, passes the tulips at Dow’s Lake and crosses the Pretoria Bridge on the way to the finish;
the half marathon takes you past historic landmarks and through some of the capital’s liveliest neighbourhoods;
the 2K heads down Elgin Street, then loops along the Rideau Canal.

On the marathon and half, water and Xact stations sit roughly every 3 km, with cooling and misting stations, portable toilets at every water stop and full medical support along the route. Xact Nutrition stations are at 8.5K, 22K and 32.5K on the marathon, and at 15.25K on the half.

The marathon cut-off

Two numbers to keep in mind if you’re aiming for a relaxed finish:

you need to reach the 27 km mark, near the Pretoria Bridge, by 11:30 a.m. — otherwise you may be redirected to the finish line;
you’re expected to finish within 7 hours.

With a 7:00 a.m. start, that gives you four and a half hours for the first 27 km.

Registration

You register online through runottawa.ca, on the Let’s Do This platform. Two tips straight from the official pages:

don’t wait on the half marathon — it’s the first race to sell out;
only runners registered before May 1 get their first name printed on their bib.

Your entry covers the finisher medal, the bib, Xact fuel and hydration on course, chip timing and recovery food. The souvenir race shirt is a paid add-on. Entry fees change over the season, so check the current rates on the organizer’s site.

Bibs are picked up at the race expo, which was held in 2026 at the Carleton University Fieldhouse.

Running Ottawa 2027 with The Run Away

If you’d rather just show up and run, that’s exactly what we organize. Our Ottawa Marathon 2027 getaway runs May 28–30, 2027:

your marathon or half marathon bib is included — we take care of the registration;
we leave Montreal on Friday by organized carpool;
2 nights at the Lord Elgin Hotel, a few minutes’ walk from the start line;
5 rooms only, to keep the group small.

Bookings are open: packages and prices are on the trip page, and to book your spot, drop us a line.

FAQ

When is the Ottawa Marathon 2027?

Sunday, May 30, 2027, with a 7:00 a.m. start at Ottawa City Hall. The half marathon starts the same morning at 9:00 a.m.; the 2K, 5K and 10K are on the Saturday.

Is the Ottawa Marathon a Boston qualifier?

Yes. The course is certified, and Run Ottawa lists the race as a Boston Marathon qualifying event.

What is the time limit for the Ottawa Marathon?

Seven hours, with a cut-off at the 27 km mark at 11:30 a.m.

Do I need to register myself if I travel with The Run Away?

No. For the 2027 edition, your marathon or half marathon bib is included in the getaway.