The 1971 US Open was a tennis tournament that took place on the outdoor grass courts at the West Side Tennis Club in Forest Hills, Queens, in New York City, USA.

The tournament ran from 1 September until 12 September.

It was the 91st staging of the US Open, and the fourth Grand Slam tennis event of 1971.

[4] Stan Smith defeated Jan Kodeš, 3–6, 6–3, 6–2, 7–6(5–3) [1] Billie Jean King defeated Rosemary Casals, 6–4, 7–6 [2] John Newcombe / Roger Taylor defeated Stan Smith / Erik van Dillen, 6–7, 6–3, 7–6, 4–6, [5-3] [3] Rosemary Casals / Judy Tegart Dalton defeated Gail Chanfreau / Françoise Dürr, 6–3, 6–3 [2] Billie Jean King / Owen Davidson defeated Betty Stöve / Robert Maud, 6–3, 7–5 [2]