Billie Jean King defeated Rosemary Casals in the final, 6–4, 7–6(5–2) to win the women's singles tennis title at the 1971 US Open.

Margaret Court was the two-time reigning champion, but did not participate this year.

1 and 18-time major singles champion Chris Evert competed in the main draw; she lost to King in the semifinals.

Evert competed in 19 consecutive US Opens until her retirement in 1989, and failed to reach the semifinals only twice in that span.

Billie Jean King is the champion; others show the round in which they were eliminated.