The 1991 FIA Sportscar World Championship season was the 39th season of FIA World Sportscar Championship motor racing. It featured the 1991 FIA Sportscar World Championship, which was contested over an eight race series from 14 April to 28 October 28, 1991. The series was open to Group C Sportscars, with Category 1 cars complying with new 1991 Group C rules and Category 2 cars running under the pre 1991 regulations. Teo Fabi won the Drivers Championship and Silk Cut Jaguar won the Teams title.

The World Sportscar Championship was the world series run for sports car racing by the FIA from 1953 to 1992. The championship evolved from a small collection of the most important sportscar, endurance, and road racing events in Europe and North America with dozens of gentleman drivers at the grid to a professional racing series where the world's largest automakers spent millions of dollars per year.