The 73rd Boat Race took place on 30 March 1921. Held annually, the Boat Race is a side-by-side rowing race between crews from the Universities of Oxford and Cambridge along the River Thames. Cambridge, with the heavier crew, went into the race as reigning champions, having won the previous year's race. In total, nine of the participants in this year's race had previous Boat Race experience, and five had won a silver medal in the 1920 Summer Olympics. In this year's race, umpired by former rower Frederick I. Pitman, Cambridge won by one length in a time of 19 minutes 45 seconds. It was Cambridge's third consecutive win, the fastest winning time since 1913 and the narrowest margin of victory since 1913. The result took the overall record to 39–33 in Oxford's favour.