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, 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.

Ken Rosewall (AUS) defeated Lew Hoad (AUS) 4–6, 6–2, 6–3, 6–3

Shirley Fry (USA) defeated Althea Gibson (USA) 6–3, 6–4