| 1958 U.S. National Championships | |
|---|---|
| Date | 29 August – 7 September |
| Edition | 78th |
| Category | Grand Slam (ILTF) |
| Surface | Grass |
| Location | Forest Hills, Queens New York City, United States |
| Venue | West Side Tennis Club |
| Champions | |
| Men's singles | |
.svg.png.webp){kind=small} Ashley Cooper[1] | |
| Women's singles | |
 Althea Gibson | |
| Men's doubles | |
| Alex Olmedo / Ham Richardson | |
| Women's doubles | |
| Jeanne Arth / Darlene Hard | |
| Mixed doubles | |
| Margaret Osborne / Neale Fraser | |
The 1958 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 29 August until 7 September. It was the 78th staging of the U.S. National Championships, and the fourth Grand Slam tennis event of the year.
Finals
Men's singles
Ashley Cooper defeated Malcolm Anderson 6–2, 3–6, 4–6, 10–8, 8–6
Women's singles
Althea Gibson defeated Darlene Hard 3–6, 6–1, 6–2
Men's doubles
Alex Olmedo (USA) / Ham Richardson (USA) defeated Sam Giammalva (USA) / Barry MacKay (USA) 3–6, 6–3, 6–4, 6–4 [2]
Women's doubles
Jeanne Arth (USA) / Darlene Hard (USA) defeated Althea Gibson (USA) / 
Maria Bueno (BRA) 2–6, 6–3, 6–4 [3]
Mixed doubles
Margaret Osborne (USA) / Neale Fraser (AUS) defeated Maria Bueno (BRA) / Alex Olmedo (USA) 6–4, 3–6, 9–7 [4]