The 1971 Canadian Grand Prix was a Formula One motor race held at Mosport Park on September 19, 1971. It was race 10 of 11 in both the 1971 World Championship of Drivers and the 1971 International Cup for Formula One Manufacturers. The events of the Formula Ford race meant that the Grand Prix was delayed, and when it did start, it was raining and thick fog had arrived. Jackie Stewart took the win after the race was stopped after 64 laps of the scheduled 80 due to the weather. American Mark Donohue finished third on his F1 debut. This was the first ever Formula One race to be red flagged.