1989 Player's Canadian Open – Men's singles

Ivan Lendl was the defending champion.

Lendl successfully defended his title, defeating John McEnroe 6–1, 6–3 in the final.

Seeds

 * 1)  Ivan Lendl (champion)
 * 2) 🇺🇸 John McEnroe (final)
 * 3) 🇺🇸 Andre Agassi (semifinals)
 * 4) 🇺🇸 Tim Mayotte (third round)
 * 5) 🇺🇸 Kevin Curren (third round)
 * 6) 🇺🇸 Jay Berger (semifinals)
 * 7)  Miloslav Mečíř (second round)
 * 8) 🇫🇷 Yannick Noah (second round)
 * 9) 🇦🇷 Guillermo Pérez Roldán (second round)
 * 10)  Goran Ivanišević (first round)
 * 11) 🇺🇸 Glenn Layendecker (first round)
 * 12) 🇨🇦 Andrew Sznajder (quarterfinals)
 * 13) 🇳🇿 Kelly Evernden (third round)
 * 14) 🇺🇸 Todd Witsken (second round)
 * 15) 🇺🇸 Richey Reneberg (third round)
 * 16) 🇺🇸 Jimmy Arias (third round)