1991 Volvo San Francisco
Date	February 4–10
Edition	103rd
Category	World Series
Draw	32S / 16D
Prize money	$225,000
Surface	Carpet / indoor
Location	San Francisco, U.S.
Venue	San Francisco Civic Auditorium
Champions
Singles
Darren Cahill[1]
Doubles
Wally Masur / Jason Stoltenberg[2]
← 1990 · Pacific Coast Championships · 1992 →

The 1991 Volvo San Francisco was a men's tennis tournament played on indoor carpet courts at the San Francisco Civic Auditorium in San Francisco, California in the United States and was part of the World Series of the 1991 ATP Tour. It was the 103rd edition of the tournament and was held from February 4 through February 10, 1991. Sixth-seeded Darren Cahill won the singles title and earned $33,800 first-prize money.^[3]

Darren Cahill defeated Brad Gilbert 6–2, 3–6, 6–4

• It was Cahill's only singles title of the year and the 2nd and last of his career.

Wally Masur / Jason Stoltenberg defeated Ronnie Båthman / Rikard Bergh 4–6, 7–6, 6–4

• ITF tournament edition details