John Convery competed as goalkeeper in the water polo competition at the 1924 Paris Olympic Games as the only Northern Irish player in an otherwise all-Dublin water polo selection. From the Falls Road in Belfast and a member of the Clonard Club, Convery secured his selection despite having conceded fifteen goals in an inter-provincial match in 1923 and thirteen goals in the final trial. Ireland received a walk-over from Austria in the first round before losing 4-2 to Czechoslovakia in the quarter-final on 15 July.