1990 Australian Open – Men's singles

Defending champion Ivan Lendl defeated Stefan Edberg in the final, 4–6, 7–6^(7–3), 5–2 ret., to win the men's singles tennis title at the 1990 Australian Open. It was his second Australian Open title and eighth and last major singles title overall. Edberg was forced to retire during the third set of the final due to a torn stomach muscle. This marked the first occasion since the 1911 Wimbledon Championships that a man withdrew during the championship match of a singles major.

Former world No. 1 John McEnroe created controversy after he was disqualified from his fourth round match for unsportsmanlike conduct. He received a warning for intimidating a linesperson, a point penalty after smashing his racket, and was defaulted for arguing with and abusing the umpire, supervisor and tournament referee.