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.

Finals

Men's singles

🇺🇸 Tony Trabert (USA) defeated 🇦🇺 Ken Rosewall (AUS) 9–7, 6–3, 6–3

Women's singles

🇺🇸 Doris Hart (USA) defeated Patricia Ward (GBR) 6–4, 6–2

Men's doubles

🇯🇵 Kosei Kamo (JPN) / 🇯🇵 Atsushi Miyagi (JPN) defeated 🇺🇸 Gerald Moss (USA) / 🇺🇸 Bill Quillian (USA) 6–2, 6–3, 3–6, 1–6, 6–4

Women's doubles

🇺🇸 Louise Brough (USA) / 🇺🇸 Margaret Osborne duPont (USA) defeated 🇺🇸 Shirley Fry (USA) / 🇺🇸 Doris Hart (USA) 6–3, 1–6, 6–3

Mixed doubles

🇺🇸 Doris Hart (USA) / 🇺🇸 Vic Seixas (USA) defeated 🇺🇸 Shirley Fry (USA) / 🇺🇸 Gardnar Mulloy (USA) 7–5, 5–7, 6–2