The 1981 Canadian Grand Prix was a Formula One motor race held on September 27, 1981, at Montreal. Jacques Laffite won the race driving for Ligier. It would prove to be Ligier's last race win for fifteen years, until the 1996 Monaco Grand Prix. Williams clinched the 1981 Constructors' Championship with one race left, as the two points scored by the Brabham team were not sufficient to allow them to catch Williams in the final race.