1999 Porsche Tennis Grand Prix – Singles

Sandrine Testud was the defending champion, but was defeated by Martina Hingis in the semifinals.

Hingis went on to win the title, defeating Mary Pierce in the final 6–4, 6–1.

Seeds
• # Martina Hingis (champion)

• # 🇺🇸 Lindsay Davenport (quarterfinals, withdrew due to left wrist injury)

• # 🇺🇸 Serena Williams (second round)

• # 🇫🇷 Mary Pierce (final)

• # Amanda Coetzer (first round)

• # 🇦🇹 Barbara Schett (quarterfinals)

• # 🇫🇷 Julie Halard-Decugis (first round)

• # 🇧🇪 Dominique Van Roost (second round)

Seeds
• # 🇷🇴 Ruxandra Dragomir (first round)

• # 🇮🇹 Silvia Farina Elia (qualifier)

• # 🇫🇷 Anne-Gaëlle Sidot (qualifying competition, lucky loser)

• # 🇸🇰 Henrieta Nagyová (first round)

• # 🇺🇸 Lisa Raymond (qualifier)

• # 🇪🇸 Magüi Serna (qualifying competition, lucky loser)

• # 🇪🇸 María Sánchez Lorenzo (qualifying competition)

• # 🇧🇪 Sabine Appelmans (qualifier)

Qualifiers
• # 🇧🇪 Sabine Appelmans

• # 🇷🇺 Elena Dementieva

• # 🇺🇸 Lisa Raymond

• # 🇮🇹 Silvia Farina Elia

Lucky losers
• # 🇪🇸 Magüi Serna

• # 🇫🇷 Anne-Gaëlle Sidot