Stefan Edberg defeated Jim Courier in the final, 6–2, 6–4, 6–0 to win the men's singles tennis title at the 1991 US Open.

Pete Sampras was the defending champion, but lost in the quarterfinals to Courier.

Five-time champion Jimmy Connors, who turned 39 during the tournament, entered as a wildcard and impressively reached the semifinals before losing to Courier.

Connors was the oldest male semifinalist at the tournament since Ken Rosewall in 1974 (whom Connors himself then defeated in the final).

Stefan Edberg was the champion; others show the round in which they were eliminated.