Switzerland competed at the 2004 Summer Olympics in Athens, Greece, from 13 to 29 August 2004.

Swiss athletes competed at every Summer Olympic Games in the modern era, except when they boycotted the 1956 Summer Olympics in Melbourne as a protest to the Soviet invasion of Hungary.

The Swiss Olympic Association sent a total of 98 athletes to the Games, 59 men and 39 women, to compete in 18 sports.

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 M = Medal race; OCS = On course side of the starting line; DSQ = Disqualified; DNF = Did not finish; DNS= Did not start; RDG = Redress given Swiss 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): Switzerland has qualified a spot in the women's duet.

Switzerland has qualified five athletes in both men's and women's triathlon.