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 City, United States.

The tournament ran from September 1 until September 6.

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.

[1][2][3][4] Joseph R. Hunt defeated Jack Kramer 6–3, 6–8, 10–8, 6–0 Pauline Betz defeated Louise Brough 6–3, 5–7, 6–3 Jack Kramer / Frank Parker defeated Bill Talbert / David Freeman 6–2, 6–4, 6–4 [5] Louise Brough / Margaret Osborne defeated Pauline Betz / Doris Hart 6–4, 6–3 [6] Margaret Osborne / Bill Talbert defeated Pauline Betz / Pancho Segura 10–8, 6–4 [7]