2009 Australian Open – Men's singles

Rafael Nadal defeated Roger Federer in the final, 7–5, 3–6, 7–6(7–3), 3–6, 6–2 to win the men's singles tennis title at the 2009 Australian Open. It was his first Australian Open title and his sixth major title overall. Nadal became the first Spaniard to win the title. It was Federer's third defeat to Nadal in a major final in the past eight months, following losses at the 2008 French Open and 2008 Wimbledon Championships.

Novak Djokovic was the defending champion, but retired due to heat stress in the quarterfinals against Andy Roddick.

The 2009 men's singles edition is considered to be one of the best Grand Slam tournaments in the Open Era. It is remembered for containing many of the best matches of the 2009 season, including the Nadal–Fernando Verdasco semifinal (lasting 5 hours and 14 minutes ) and the final. It was also the first hard court major in which Nadal reached the final.

Seeds
• 🇪🇸 Rafael Nadal (champion)

• Roger Federer (final)

• 🇷🇸 Novak Djokovic (quarterfinals, retired due to heat stress)

• 🇬🇧 Andy Murray (fourth round)

• 🇫🇷 Jo-Wilfried Tsonga (quarterfinals)

• 🇫🇷 Gilles Simon (quarterfinals)

• 🇺🇸 Andy Roddick (semifinals)

• 🇦🇷 Juan Martín del Potro (quarterfinals)

• 🇺🇸 James Blake (fourth round)

• 🇦🇷 David Nalbandian (second round)

• 🇪🇸 David Ferrer (third round)

• 🇫🇷 Gaël Monfils (fourth round, retired due to a right wrist injury)

•  Fernando González (fourth round)

• 🇪🇸 Fernando Verdasco (semifinals)

•  Stan Wawrinka (third round)

• 🇸🇪 Robin Söderling (second round)

• 🇪🇸 Nicolás Almagro (third round)

• 🇷🇺 Igor Andreev (third round)

•  Marin Čilić (fourth round)

• 🇨🇿 Tomáš Berdych (fourth round)

• 🇪🇸 Tommy Robredo (fourth round)

• 🇨🇿 Radek Štěpánek (third round)

• 🇺🇸 Mardy Fish (third round)

• 🇫🇷 Richard Gasquet (third round)

•  Ivo Karlović (second round)

• 🇷🇺 Marat Safin (third round)

• 🇪🇸 Feliciano López (first round)

• 🇫🇷 Paul-Henri Mathieu (second round)

• 🇷🇺 Dmitry Tursunov (first round)

• 🇩🇪 Rainer Schüttler (first round)

• 🇦🇹 Jürgen Melzer (third round)

• 🇩🇪 Philipp Kohlschreiber (second round)