The 1991 Formula One Season was the 42nd edition of the Formula One World Championship, organised by the Fédération Internationale de l'Automobile. A sixteen round calendar saw Ayrton Senna take seven wins on his way to a third World Championship, after a mid-season challenge by Nigel Mansell. McLaren-Honda won the Constructors' Championship through Senna and Gerhard Berger's efforts, although it was widely acknowledged that the Williams FW14 was the stronger car.