The 1981 World Sportscar Championship season was the 29th season of FIA World Sportscar Championship motor racing. It featured the 1981 FIA World Endurance Championship which was contested over a fifteen race series which ran from 31 January to 27 September. The former World Challenge for Endurance Drivers was renamed to the World Endurance Championship of Drivers for 1981 and the World Championship of Makes was renamed to the World Endurance Championship of Makes. Bob Garretson won the World Endurance Championship of Drivers and Lancia was awarded the World Endurance Championship of Makes.

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.