2005 Australian Open – Men's singles

Marat Safin defeated Lleyton Hewitt in the final, 1–6, 6–3, 6–4, 6–4 to win the men's singles tennis title at the 2005 Australian Open. It was his first Australian Open title (following two runner-up finishes in 2002 and 2004) and second and last major title overall, having previously won the 2000 US Open. Safin saved a match point en route to the title, against Roger Federer in the semifinals. Hewitt was the first Australian to reach the final since Pat Cash in 1988.

Federer was the defending champion, but lost in the semifinals to Safin in a rematch of the previous year's final, despite holding a match point in the fourth set. Federer's loss ended his 26-match winning streak dating to the 2004 US Open.

The final attracted many viewers in Australia (primarily due to the presence of countryman Hewitt), averaging 4.05 million viewers. The viewing audience remains one of the highest in Australian history. The match was broadcast in the host nation by host broadcaster the Seven Network with commentators Bruce McAvaney and two-time champion Jim Courier (in his first appearance on Australian commercial television).

This marked the first major main draw appearance of future ten-time Australian Open champion and 24-time major champion Novak Djokovic (who qualified and then lost to Safin in the first round), and the last Australian Open for four-time champion Andre Agassi. Future 22-time major champion Rafael Nadal advanced beyond the third round of a major for the first time, losing to Hewitt in the fourth round. It was also the last major in which neither Federer, Nadal, nor Djokovic reached the final until the 2014 US Open, a span of 38 events. It remains the only major where Federer, Nadal and Djokovic all competed but none of them reached the final.