The 1921 French Grand Prix (formally the XV Grand Prix de l'Automobile Club de France) 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.