The 1966 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 1 September until 12 September. It was the 86th staging of the U.S. National Championships, and the fourth Grand Slam tennis event of 1966.
Fred Stolle defeated John Newcombe 4–6, 12–10, 6–3, 6–4
Maria Bueno defeated Nancy Richey 6–3, 6–1
Roy Emerson / Fred Stolle defeated Clark Graebner / Dennis Ralston 6–4, 6–4, 6–4 
Maria Bueno / Nancy Richey defeated Billie Jean King / Rosie Casals 6–3, 6–4 
Donna Floyd Fales / Owen Davidson defeated Carol Aucamp / Ed Rubinoff 6–1, 6–3 
- ^ Collins, Bud (2010). The Bud Collins History of Tennis (2nd ed. ed.). [New York]: New Chapter Press. p. 478. ISBN 978-0942257700.
- ^ Collins, p. 480
- ^ Collins, p. 482