The 1921 French Grand Prix was a Grand Prix motor race held at Le Mans on 25 July 1921. The race was held over 30 laps of the 17.26 km circuit for a total distance of 517.8 km and was won by Jimmy Murphy driving a Duesenberg. This was the last victory for an American constructor in a major European race until the Ford GT40's triumph at the 1966 24 Hours of Le Mans as well as in a Grand Prix race until the Dan Gurney's win with the Eagle car at the 1967 Belgian Grand Prix. The race did not feature a massed start, with cars released in pairs at one-minute intervals instead.

Grand Prix motor racing, a form of motorsport competition, has its roots in organised automobile racing that began in France as early as 1894. It quickly evolved from simple road races from one town to the next, to endurance tests for car and driver. Innovation and the drive of competition soon saw speeds exceeding 100 miles per hour (160 km/h), but because early races took place on open roads, accidents occurred frequently, resulting in deaths both of drivers and of spectators. A common abbreviation used for Grand Prix racing is "GP" or "GP racing".