The 1931 Australian Championships was a tennis tournament that took place on outdoor Grass courts at the White City Tennis Club, Sydney, Australia from 27 February to 9 March. It was the 24th edition of the Australian Championships (now known as the Australian Open), the 6th held in Sydney, and the first Grand Slam tournament of the year. The singles titles were won by Australians Jack Crawford and Coral McInnes Buttsworth.
See main article: 1931 Australian Championships – Men's singles. 
Jack Crawford defeated Harry Hopman 6–4, 6–2, 2–6, 6–1
See main article: 1931 Australian Championships – Women's singles. Coral McInnes Buttsworth defeated Marjorie Cox Crawford 1–6, 6–3, 6–4
See main article: 1931 Australian Championships – Men's doubles. Charles Donohoe / Ray Dunlop defeated Jack Crawford / Harry Hopman 8–6, 6–2, 5–7, 7–9, 6–4[1]
See main article: 1931 Australian Championships – Women's doubles. Daphne Akhurst Cozens / Louie Bickerton defeated Nell Lloyd / Gwen Utz 6–0, 6–4
See main article: 1931 Australian Championships – Mixed doubles. Marjorie Cox Crawford / Jack Crawford defeated Emily Hood Westacott / Aubrey Willard 7–5, 6–4