1991 Volvo San Francisco – Singles

Andre Agassi was the defending champion, but lost in semifinals to Brad Gilbert.

Darren Cahill won the title by defeating Gilbert 6–2, 3–6, 6–4 in the final.

Seeds
• # 🇺🇸 Andre Agassi (semifinals)

• # 🇪🇨 Andrés Gómez (second round)

• # 🇺🇸 Brad Gilbert (final)

• # 🇺🇸 John McEnroe (quarterfinals)

• # 🇺🇸 Tim Mayotte (second round)

• # 🇦🇺 Darren Cahill (champion)

• # 🇦🇺 Wally Masur (semifinals)

• # Gary Muller (first round)