The 1945 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 28 August until 3 September. It was the 65th staging of the U.S. National Championships, and due to World War II it was the only Grand Slam tennis event of the year.
Frank Parker defeated William Talbert 14–12, 6–1, 6—2
Sarah Palfrey Cooke defeated Pauline Betz Addie 3–6, 8–6, 6–4
Gardnar Mulloy / Bill Talbert defeated Bob Falkenburg / Jack Tuero 12–10, 8–10, 12–10, 6–2 
Louise Brough / Margaret Osborne defeated Pauline Betz / Doris Hart 6–3, 6–3 
Margaret Osborne / Bill Talbert defeated Doris Hart / Bob Falkenberg 6–4, 6–4 
- ^ Collins, Bud (2010). The Bud Collins History of Tennis (2nd ed.). [New York]: New Chapter Press. pp. 77–78. ISBN 978-0942257700.
- ^ Collins, p. 477
- ^ Collins, p. 480
- ^ Collins, p. 482