The 1991 Canadian Grand Prix was a Formula One motor race held at Circuit Gilles Villeneuve on 2 June 1991. It was the fifth race of the 1991 FIA Formula One World Championship.

The race was won by Nelson Piquet, driving a Benetton-Ford. Piquet took the 23rd and final win of his F1 career after old rival Nigel Mansell, driving a Williams-Renault, suddenly stopped halfway round the last lap while leading by almost a minute. Stefano Modena took second in a Tyrrell-Honda, while Mansell's team-mate Riccardo Patrese was third, having started from pole position. Piquet's win was the first for a car using Pirelli tyres since the 1986 Mexican Grand Prix and the last win for a car using Pirelli tyres until the 2011 Australian Grand Prix.