2005 French Open – Men's singles

Rafael Nadal defeated Mariano Puerta in the final, 6–7(6–8), 6–3, 6–1, 7–5 to win the men's singles tennis title at the 2005 French Open. It was his first major title, the first of a record 14 French Open titles, and the first of 22 major men's singles titles overall. Nadal won the French Open on his tournament debut, the first man to do so since Mats Wilander in 1982, and was the youngest champion since Michael Chang in 1989, at 19 years and two days old when he won the title.

Gastón Gaudio was the defending champion, but lost in the fourth round to David Ferrer.

Roger Federer was attempting to complete the career Grand Slam, but was defeated in the semifinals by Nadal. It was the first of four consecutive years that Nadal would defeat Federer at the tournament; Federer would eventually complete the career Grand Slam in 2009.

This was the first French Open where future three-time champion Novak Djokovic competed, and marked the first time he won a major match. Future champion Stanislas Wawrinka also made his first appearance at a major, losing in the third round to Puerta. 1999 champion Andre Agassi made his last French Open appearance, losing a five-set match to Jarkko Nieminen in the first round.

Seeds
• Roger Federer (semifinals)

• 🇺🇸 Andy Roddick (second round)

• 🇷🇺 Marat Safin (fourth round)

• 🇪🇸 Rafael Nadal (champion)

• 🇦🇷 Gastón Gaudio (fourth round)

• 🇺🇸 Andre Agassi (first round)

• 🇬🇧 Tim Henman (second round)

• 🇦🇷 Guillermo Coria (fourth round)

• 🇦🇷 Guillermo Cañas (quarterfinals)

• 🇦🇷 David Nalbandian (fourth round)

• 🇸🇪 Joachim Johansson (withdrew due to an elbow injury)

• 🇷🇺 Nikolay Davydenko (semifinals)

• Ivan Ljubičić (first round)

• 🇪🇸 Carlos Moyá (fourth round)

• 🇪🇸 Tommy Robredo (quarterfinals)

• 🇨🇿 Radek Štěpánek (third round)

• 🇸🇰 Dominik Hrbatý (first round)

•  Mario Ančić (third round)

• 🇸🇪 Thomas Johansson (second round)

• 🇪🇸 David Ferrer (quarterfinals)

• 🇩🇪 Tommy Haas (third round)

•  Nicolás Massú (first round)

• 🇫🇷 Sébastien Grosjean (fourth round)

• 🇪🇸 Feliciano López (first round)

•  Fernando González (third round)

• 🇨🇿 Jiří Novák (second round)

• 🇮🇹 Filippo Volandri (third round, retired due to a hand injury)

• 🇩🇪 Nicolas Kiefer (fourth round, withdrew due to a neck injury)

• 🇷🇺 Mikhail Youzhny (second round)

• 🇫🇷 Richard Gasquet (third round)

• 🇦🇷 Juan Ignacio Chela (second round)

• 🇪🇸 Juan Carlos Ferrero (third round)

• 🇸🇪 Robin Söderling (second round)