The 1956 U.S. National Championships (now known as the US Open) was a tennis tournament that took place on the outdoor grass courts at the West Side Tennis Club, Forest Hills in New York City, United States. The tournament ran from 31 August until 9 September. It was the 76th staging of the U.S. National Championships, and the fourth Grand Slam tennis event of the year.
See main article: 1956 U.S. National Championships – Men's singles. 
Ken Rosewall (AUS) defeated Lew Hoad (AUS) 4–6, 6–2, 6–3, 6–3
See main article: 1956 U.S. National Championships – Women's singles. 
Shirley Fry (USA) defeated Althea Gibson (USA) 6–3, 6–4
Lew Hoad (AUS) / Ken Rosewall (AUS) defeated Ham Richardson (USA) / Vic Seixas (USA) 6–2, 6–2, 3–6, 6–4 [1]
Louise Brough (USA) / Margaret Osborne (USA) defeated Shirley Fry (USA) / Betty Pratt (USA) 6–3, 6–0 [2]
Margaret Osborne (USA) / Ken Rosewall (AUS) defeated Darlene Hard (USA) / Lew Hoad (AUS) 9–7, 6–1 [3]