Uruguay competed at the 2004 Summer Olympics in Athens, Greece, from 13 to 29 August 2004. This was the nation's eighteenth appearance at the Olympics, except the 1980 Summer Olympics in Moscow, because of its full support to the United States boycott.
The Uruguayan Olympic Committee (, COU) sent a total of 15 athletes to the Games, 13 men and 2 women, to compete in 6 different sports. Four athletes from the Uruguayan team had previously competed in Sydney, including track cyclist Milton Wynants, who won the bronze in the men's points race, and backstroke swimmer Serrana Fernández, who later carried the nation's flag in the opening ceremony.
Following Wynants' blistering finish in men's track cycling from Sydney four years earlier, Uruguay, however, failed to win a single Olympic medal in Athens.
Uruguayan athletes have so far achieved qualifying standards in the following athletics events (up to a maximum of 3 athletes in each event at the 'A' Standard, and 1 at the 'B' Standard).
<small>Qualification Legend: Q = Qualify to final; q = Qualify to semifinal</small>
Uruguayan rowers qualified the following boats:
<small>Qualification Legend: FA=Final A (medal); FB=Final B (non-medal); FC=Final C (non-medal); FD=Final D (non-medal); FE=Final E (non-medal); FF=Final F (non-medal); SA/B=Semifinals A/B; SC/D=Semifinals C/D; SE/F=Semifinals E/F; R=Repechage</small>
Uruguayan sailors have qualified one boat for each of the following events.
<small>M = Medal race; OCS = On course side of the starting line; DSQ = Disqualified; DNF = Did not finish; DNS= Did not start; RDG = Redress given</small>
Uruguayan swimmers earned qualifying standards in the following events (up to a maximum of 2 swimmers in each event at the A-standard time, and 1 at the B-standard time):