Seamus Patrick McGrath (born March 5, 1976, in Mississauga, Ontario) is a retired Canadian professional mountain biker. Riding the sport for more than 15 years as a member of the Canadian national team, McGrath has won two medals in mountain biking at the Commonwealth Games (2002 and 2006), and later represented his nation Canada in two editions of the Olympic Games (2004 and 2008). Before retiring to focus on and organize the annual Tour de Victoria race in late 2008, McGrath also trained and raced professionally for Haro-Lee Dungaree and Fuji Bikes under an exclusive sponsorship contract.