Michael Chang defeated Jay Berger in the final, 4–6, 6–3, 7–6(7–3) to win the men's singles tennis title at the 1990 Canadian Open. With the win, Chang became the youngest Masters champion in history.
Ivan Lendl was the three-time reigning champion, but did not compete that year.
A champion seed is indicated in bold text while text in italics indicates the round in which that seed was eliminated. The top eight seeds received a bye into the second round.