The Tamarack Ottawa Race Weekend is Canada’s largest running festival held annually in May in Ottawa, Ontario. Established in 1975, it features multiple races attracting both elite athletes and recreational runners from around the world, including the Boston Marathon qualifying Tartan Ottawa International Marathon.
Participants enjoy scenic courses passing landmarks such as Parliament Hill and the Rideau Canal, with comprehensive on-course support including periodic water, nutrition, and misting stations, medical services, and lively cheer zones. The Green Bib option offers runners a chance to fundraise for the Desjardins Charity Challenge instead of receiving a medal.