1989 OTB Open – Men's singles

Tim Mayotte was the defending champion, but did not participate this year.

Simon Youl won the tournament, beating Scott Davis in the final, 2–6, 6–4, 6–4.

Seeds

 * 1) 🇺🇸 Dan Goldie (semifinals)
 * 2) 🇺🇸 Richard Matuszewski (first round)
 * 3) 🇮🇳 Ramesh Krishnan (quarterfinals)
 * 4) 🇺🇸 Scott Davis (final)
 * 5) 🇦🇺 John Frawley (first round)
 * 6) 🇨🇦 Martin Laurendeau (second round)
 * 7) 🇺🇸 Jeff Tarango (quarterfinals)
 * 8) 🇨🇦 Glenn Michibata (semifinals)