| 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 | |
| .svg.png.webp) Ken Rosewall[1] | |
| Women's singles | |
|  Shirley Fry | |
| Men's doubles | |
| .svg.png.webp) Lew Hoad / .svg.png.webp) Ken Rosewall | |
| Women's doubles | |
|  Louise Brough /  Margaret Osborne duPont | |
| Mixed doubles | |
|  Margaret Osborne duPont / .svg.png.webp) Ken Rosewall | |
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.
Finals
Men's singles
.svg.png.webp) Ken Rosewall (AUS) defeated
 Ken Rosewall (AUS) defeated .svg.png.webp) Lew Hoad (AUS) 4–6, 6–2, 6–3, 6–3
 Lew Hoad (AUS) 4–6, 6–2, 6–3, 6–3
Women's singles
 Shirley Fry (USA) defeated
 Shirley Fry (USA) defeated  Althea Gibson  (USA) 6–3, 6–4
 Althea Gibson  (USA) 6–3, 6–4
Men's doubles
.svg.png.webp) Lew Hoad (AUS) /
 Lew Hoad (AUS) / .svg.png.webp) Ken Rosewall (AUS) defeated
 Ken Rosewall (AUS) defeated  Ham Richardson (USA) /
 Ham Richardson (USA) /  Vic Seixas (USA) 6–2, 6–2, 3–6, 6–4 [2]
 Vic Seixas (USA) 6–2, 6–2, 3–6, 6–4 [2]
Women's doubles
 Louise Brough (USA) /
 Louise Brough (USA) /  Margaret Osborne (USA) defeated
 Margaret Osborne (USA) defeated  Shirley Fry (USA) /
 Shirley Fry (USA) /  Betty Pratt (USA) 6–3, 6–0 [3]
 Betty Pratt (USA) 6–3, 6–0 [3]
Mixed doubles
 Margaret Osborne (USA) /
 Margaret Osborne (USA) /  .svg.png.webp) Ken Rosewall (AUS) defeated
 Ken Rosewall (AUS) defeated  Darlene Hard (USA) /
 Darlene Hard (USA) / .svg.png.webp) Lew Hoad (AUS) 9–7, 6–1 [4]
 Lew Hoad (AUS) 9–7, 6–1 [4]