2025 Australian Open – Men's singles

Defending champion Jannik Sinner defeated Alexander Zverev in the final, 6–3, 7–6^(7–4), 6–3 to win the men's singles tennis title at the 2025 Australian Open. It was his second Australian Open title and third major title overall. Sinner was the youngest man to defend the title since Jim Courier in 1993, and the youngest to defend their first major title since Rafael Nadal at the 2006 French Open.

Novak Djokovic retired in his semifinal match against Zverev due to injury. Djokovic's second-round match marked his 430th career major main draw singles match, surpassing Roger Federer's all-time record. Carlos Alcaraz was vying to become the youngest man to complete the career Grand Slam in singles, but he lost to Djokovic in the quarterfinals.

João Fonseca was the first teenager to defeat a top-10 opponent on their major debut since Mario Ančić defeated Federer at the 2002 Wimbledon Championships. Learner Tien was the youngest man to reach the fourth round at the Australian Open since Nadal in 2005. With the victories of Fonseca, Tien and Jakub Menšík over top-10-ranked opponents, this marked the third occasion in which three different teenagers had accomplished the feat at a major (after the 1990 and 2006 French Opens).

With his victory over fourth seed Taylor Fritz in the third round, Gaël Monfils at 38 years old, was the oldest man to defeat a top-5 seeded opponent at a major since Ken Rosewall defeated John Newcombe at the 1974 US Open, and the oldest to do so at the Australian Open since the introduction of the ATP rankings.

Hady Habib became the first Lebanese player, male or female, to qualify for and win a match in the main draw of a major in the Open Era.