The 2004 ATP Tour was the global elite men's professional tennis circuit organised by the Association of Tennis Professionals (ATP) for the 2004 tennis season.

The ATP Tour is the elite tour for professional tennis organised by the ATP.

The ATP Tour includes the four Grand Slam tournaments, the Tennis Masters Cup, the ATP Masters Series, the International Series Gold and the International Series tournaments.

The table below shows the 2004 ATP Tour schedule.

Players and titles won (Grand Slam, Masters Cup, and Olympic titles in bold), listed in order of number of titles: The following players won their first title: Titles won by nation: Following is a list of notable players (winners of a main tour title, and/or part of the ATP rankings top 100 (singles) or top 50 (doubles) for at least one week) who announced their retirement from professional tennis, became inactive (after not playing for more than 52 weeks), or were permanently banned from playing, during the 2004 season: