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

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

Women's singles

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

Men's doubles

🇦🇺 Lew Hoad (AUS) / 🇦🇺 Ken Rosewall (AUS) defeated 🇺🇸 Ham Richardson (USA) / 🇺🇸 Vic Seixas (USA) 6–2, 6–2, 3–6, 6–4

Women's doubles

🇺🇸 Louise Brough (USA) / 🇺🇸 Margaret Osborne (USA) defeated 🇺🇸 Shirley Fry (USA) / 🇺🇸 Betty Pratt (USA) 6–3, 6–0

Mixed doubles

🇺🇸 Margaret Osborne (USA) / 🇦🇺 Ken Rosewall (AUS) defeated 🇺🇸 Darlene Hard (USA) / 🇦🇺 Lew Hoad (AUS) 9–7, 6–1