The 1943 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 6 September. It was the 63rd staging of the U.S. National Championships and due to World War II it was the only Grand Slam tennis event of the year.
Joseph R. Hunt defeated Jack Kramer 6–3, 6–8, 10–8, 6–0
Pauline Betz Addie defeated Louise Brough Clapp 6–3, 5–7, 6–3
Jack Kramer / Frank Parker defeated Bill Talbert / David Freeman 6–2, 6–4, 6–4 
Louise Brough / Margaret Osborne defeated Pauline Betz / Doris Hart 6–4, 6–3 
Margaret Osborne / Bill Talbert defeated Pauline Betz / Pancho Segura 10–8, 6–4