1989 Cincinnati Open – Singles

Mats Wilander was the defending champion but lost in the semifinals to Stefan Edberg.

Brad Gilbert won in the final 6–4, 2–6, 7–6 against Edberg.

Seeds
• # Boris Becker (semifinals)

• # 🇸🇪 Stefan Edberg (final)

• # 🇸🇪 Mats Wilander (semifinals)

• # 🇺🇸 Michael Chang (quarterfinals)

• # 🇺🇸 Brad Gilbert (champion)

• # 🇺🇸 Aaron Krickstein (third round)

• # Andrei Chesnokov (second round)

• # 🇵🇪 Jaime Yzaga (quarterfinals)

• # 🇸🇪 Anders Järryd (first round)

• # 🇸🇪 Jonas Svensson (quarterfinals)

• # 🇦🇺 John Fitzgerald (first round)

• # 🇪🇨 Andrés Gómez (quarterfinals)

• # 🇸🇪 Peter Lundgren (first round)

• # 🇺🇸 Jim Courier (third round)

• # Alexander Volkov (first round)

• # 🇺🇸 Derrick Rostagno (first round)