1991 Lufthansa Cup German Open – Singles

Steffi Graf defeated Arantxa Sánchez Vicario in the final, 6–3, 4–6, 7–6(8–6) to win the singles tennis title at the 1991 WTA German Open.

Monica Seles was the reigning champion, but chose not to participate.

Seeds
The top eight seeds received a bye to the second round. • # Steffi Graf (champion)

• # 🇦🇷 Gabriela Sabatini (third round)

• # 🇺🇸 Mary Joe Fernández (third round)

• # Jana Novotná (semifinal)

• # 🇪🇸 Arantxa Sánchez Vicario (final)

• # 🇧🇬 Katerina Maleeva (second round)

• # 🇺🇸 Jennifer Capriati (semifinal)

• # Helena Suková (third round)

• # Leila Meskhi (first round)

• # 🇫🇷 Nathalie Tauziat (first round)

• # Natalia Zvereva (third round)

• # 🇮🇹 Sandra Cecchini (third round)

• # 🇦🇹 Judith Wiesner (first round)

• # 🇩🇪 Anke Huber (quarterfinal)

• # 🇵🇪 Laura Gildemeister (second round)

• # 🇦🇷 Mercedes Paz (second round)