1991 Virginia Slims of Philadelphia – Singles

The last edition of the tournament was in 1979, which was won by Wendy Turnbull.

Monica Seles won the title by defeating Jennifer Capriati 7–5, 6–1 in the final.

Seeds
The top four seeds received a bye to the second round. • # Monica Seles (champion)

• # 🇦🇷 Gabriela Sabatini (semifinals)

• # 🇪🇸 Arantxa Sánchez Vicario (semifinals)

• # 🇺🇸 Jennifer Capriati (final)

• # 🇺🇸 Mary Joe Fernández (first round)

• # 🇪🇸 Conchita Martínez (quarterfinals)

• # Manuela Maleeva-Fragnière (quarterfinals)

• # 🇺🇸 Zina Garrison (quarterfinals)