Races Marathon · Ottawa, Canada
Ottawa Marathon
Ottawa Marathon is a flat marathon in Ottawa, Canada, held each May. Canada's largest marathon: an ultra-flat capital course that crosses the Ottawa River into Quebec and back, redesigned for fast times. Late May is usually 10-18C; a warm year can push into the low 20s by the finish. Flat courses like Ottawa's reward metronomic pacing — the danger is going out faster than goal pace because it feels cheap early.
Page rebuilt 2026-10-02 · race facts not independently verified — confirm dates and entries on the official race site
When
May
every year
Course
flat
Marathon
Conditions
Late May is usually 10-18C; a warm year can push into the low 20s by the finish.
Racing this course well
Canada's largest marathon: an ultra-flat capital course that crosses the Ottawa River into Quebec and back, redesigned for fast times.
Flat courses like Ottawa's reward metronomic pacing — the danger is going out faster than goal pace because it feels cheap early.
Pick your goal for Ottawa
Pace charts, weekly structure and timelines for the most common marathon goals:
We don’t hold a confirmed date for this edition, so any countdown comes from the date you enter here.
Build your training around Ottawa Marathon.
RunV works backwards from race day to today and rearranges the weeks when life interrupts. It does not adapt to this specific course — the pacing guidance above is where the course knowledge is.
Everything above stays free and complete — this is an optional next step, not a paywall.
Asked often
- When is the Ottawa Marathon?
- It is held each May in Ottawa, Canada. Check the official Ottawa Marathon site for the exact date and entry windows.
- Is the Ottawa Marathon course flat?
- Canada's largest marathon: an ultra-flat capital course that crosses the Ottawa River into Quebec and back, redesigned for fast times.
- How should I train for the Ottawa Marathon?
- Match your preparation to Ottawa Marathon's profile and the May weather, then protect consistency — RunV's adaptive plan recalibrates after every run so one bad week never derails the block.
Not sure what to target? Predict your marathon time from a recent race →
More marathon races
Build for Ottawa — around your actual life
RunV engineers your block backwards from race day in May — and rebuilds it every time training doesn't go to script.
