The 1920–21 FA Cup was the 46th season of the world's oldest football knockout competition; the Football Association Challenge Cup, or FA Cup for short. The large number of clubs entering the tournament from lower down the English football league system meant that the competition started with an Extra Preliminary and Preliminary rounds prior to six Qualifying rounds. The 12 victorious teams from the Sixth Round Qualifying (from the 466 who contested the qualifying phase) progressed to the First Round Proper.