1956 U.S. National Championships
Date	31 August – 9 September
Edition	76th
Category	Grand Slam (ILTF)
Surface	Grass
Location	Chestnut Hill, Massachusetts Forest Hills, Queens, New York City United States
Venue	Longwood Cricket Club West Side Tennis Club
Champions
Men's singles
Ken Rosewall[1]
Women's singles
Shirley Fry
Men's doubles
Lew Hoad / Ken Rosewall
Women's doubles
Louise Brough / Margaret Osborne duPont
Mixed doubles
Margaret Osborne duPont / Ken Rosewall
← 1955 · U.S. National Championships · 1957 →

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.

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

Lew Hoad (AUS) / Ken Rosewall (AUS) defeated Ham Richardson (USA) / Vic Seixas (USA) 6–2, 6–2, 3–6, 6–4 ^[2]

Louise Brough (USA) / Margaret Osborne (USA) defeated Shirley Fry (USA) / Betty Pratt (USA) 6–3, 6–0 ^[3]

Margaret Osborne (USA) / Ken Rosewall (AUS) defeated Darlene Hard (USA) / Lew Hoad (AUS) 9–7, 6–1 ^[4]

• Official US Open website