Gastón Gaudio defeated Guillermo Coria in the final, 0–6, 3–6, 6–4, 6–1, 8–6 to win the men's singles tennis title at the 2004 French Open.

Juan Carlos Ferrero was the defending champion, but was defeated in the second round by Igor Andreev: his first loss at the French Open prior to the semifinals.

1 and three-time champion Gustavo Kuerten, his last pre-quarterfinal exit from a major until the 2013 Wimbledon Championships (a run of 36 quarterfinals or better in a row).

Until 2023, this was the last French Open not to feature future 14-time champion Rafael Nadal, who withdrew prior to the tournament due to an ankle injury sustained in Estoril in April.

This was the first major in the Open Era to feature four Argentines in the quarterfinals, those being Gaudio, Coria, David Nalbandian, and Juan Ignacio Chela.