See main article: 1970 US Open (tennis). 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. It was her second US Open singles title.
Margaret Court was the two-time reigning champion, but did not defend her title.
This tournament marked the first major in which future world No. 1 and 18-time major 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.
The seeded players are listed below. Billie Jean King is the champion; others show the round in which they were eliminated.
Billie Jean King (champion) Rosemary Casals (runner-up)
Virginia Wade (withdrew before the tournament began)
Kerry Melville (semifinalist)
Françoise Dürr (third round) Judy Tegart-Dalton (quarterfinalist) Nancy Richey (third round) Julie Heldman (third round)