The 1971 Pacific Southwest Open was a combined men's and women's tennis tournament played on outdoor hard courts at the Los Angeles Tennis Center in Los Angeles, California in the United States and was part of the 1971 Grand Prix tennis circuit. It was the 45th edition of the tournament and ran from September 20 through September 26, 1971. Pancho Gonzales, aged 43, won the men's singles title and $10,000 first prize money. The women's singles title was divided between Billie Jean King and Rosie Casals.
Pancho Gonzales defeated Jimmy Connors 2–6, 6–3, 6–3
Billie Jean King defeated Rosie Casals 6–6, div.
John Alexander / Phil Dent defeated Frank Froehling / Clark Graebner 7–6, 6–4
Rosie Casals / Billie Jean King defeated Françoise Dürr / Judy Tegart Dalton 6–2, 5–7, 7–6