Jack Crawford defeated Harry Hopman 6–4, 6–2, 2–6, 6–1 in the final to win the men's singles tennis title at the 1931 Australian Championships.
The seeded players are listed below. Jack Crawford is the champion; others show the round in which they were eliminated.
Jack Crawford (champion) Harry Hopman (finalist) Gar Moon (quarterfinals) Jack Cummings (semifinals) Clifford Sproule (quarterfinals) Ray Dunlop (first round) Harry Hassett (quarterfinals) Don Turnbull (semifinals)