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, USA. 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.
Ken Rosewall (AUS) defeated Lew Hoad (AUS) 4–6, 6–2, 6–3, 6–3
Shirley Fry Irvin (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 
Louise Brough (USA) / Margaret Osborne (USA) defeated Shirley Fry (USA) / Betty Pratt (USA) 6–3, 6–0 
Margaret Osborne (USA) / Ken Rosewall (AUS) defeated Darlene Hard (USA) / Lew Hoad (AUS) 9–7, 6–1 
- ^ Collins, Bud (2010). The Bud Collins History of Tennis (2nd ed. ed.). [New York]: New Chapter Press. p. 477. ISBN 978-0942257700.
- ^ Collins, p. 480
- ^ Collins, p. 482