The 1955 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 2 September until 11 September. It was the 75th staging of the U.S. National Championships, and the fourth Grand Slam tennis event of the year.
See main article: 1955 U.S. National Championships – Men's singles. 
Tony Trabert (USA) defeated 
Ken Rosewall (AUS) 9–7, 6–3, 6–3
See main article: 1955 U.S. National Championships – Women's singles. Doris Hart (USA) defeated Patricia Ward (GBR) 6–4, 6–2
Kosei Kamo (JPN) / Atsushi Miyagi (JPN) defeated Gerald Moss (USA) / Bill Quillian (USA) 6–2, 6–3, 3–6, 1–6, 6–4 [1]
Louise Brough (USA) / Margaret Osborne duPont (USA) defeated Shirley Fry (USA) / Doris Hart (USA) 6–3, 1–6, 6–3 [2]
Doris Hart (USA) / Vic Seixas (USA) defeated Shirley Fry (USA) / Gardnar Mulloy (USA) 7–5, 5–7, 6–2 [3]