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, USA. 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.
Ashley Cooper defeated Malcolm Anderson 6–2, 3–6, 4–6, 10–8, 8–6
Althea Gibson defeated Darlene Hard 3–6, 6–1, 6–2
Alex Olmedo (USA) / Ham Richardson (USA) defeated Sam Giammalva (USA) / Barry MacKay (USA) 3–6, 6–3, 6–4, 6–4 
Jeanne Arth (USA) / Darlene Hard (USA) defeated Althea Gibson (USA) / Maria Bueno (BRA) 2–6, 6–3, 6–4 
Margaret Osborne (USA) / Neale Fraser (AUS) defeated Maria Bueno (BRA) / Alex Olmedo (USA) 6–3, 3–6, 9–7 
- ^ Collins, Bud (2010). The Bud Collins History of Tennis (2nd ed. ed.). [New York]: New Chapter Press. p. 477. ISBN 978-0942257700.
- ^ Collins, p. 480
- ^ Collins, p. 482