The 1964 World Sportscar Championship season was the 12th season of FIA 'World Sportscar Championship' motor racing. It featured the 1964 International Championship for GT Manufacturers which was open to Group 3 GT cars and was contested from 16 February 1964 to 11 October 1964 over a twenty race series. Titles were awarded in three engine capacity divisions:Division I – Under 1300cc Division II – Under 2000cc Division III – Over 2000cc

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.