Slovenia competed at the 2004 Summer Olympics in Athens, Greece, from 13 to 29 August 2004. This was the nation's fourth consecutive appearance at the Summer Olympics since the post-Yugoslav era. The Slovenian Olympic Committee sent the nation's largest ever delegation to the Games in Olympic history. A total of 79 athletes, 56 men and 23 women, competed in 10 sports. For the second consecutive time, men's handball was the only team-based sport in which Slovenia had its representation at these Games. The Slovenian team featured three defending Olympic champions from Sydney: double sculls pair Iztok Čop and Luka Špik, and rifle shooter Rajmond Debevec, who became the first Slovenian to compete in six Olympic Games. Sprinter Merlene Ottey, who granted a dual citizenship in 2002, also set a historic milestone as the first female track and field athlete to participate in seventh Olympics, although she appeared for her native Jamaican team in previous editions. Handball team goalkeeper Beno Lapajne was appointed by the committee to carry the Slovenian flag in the opening ceremony. Slovenia left Athens with a total of four medals, one silver and bronze, failing to achieve an Olympic gold for the first time since the 1996 Summer Olympics in Atlanta. Unable to defend their Olympic rowing title from the previous Games, Čop and Špik managed to settle only for the silver after losing out to France by two seconds in the men's double sculls. Meanwhile, the remaining medals were awarded to the athletes for the first time in women's judo and sailing.
Qualification Legend: Q = Qualify to final; q = Qualify to semifinal
Cycling
Road
Handball
Men's tournament
;Roster ;Group play ;Classification match
Judo
Five Slovenian judoka qualified for the 2004 Summer Olympics. ;Men ;Women
Rowing
Slovenian rowers qualified the following boats: ;Men Qualification Legend: FA=Final A ; FB=Final B ; FC=Final C ; FD=Final D ; FE=Final E ; FF=Final F ; SA/B=Semifinals A/B; SC/D=Semifinals C/D; SE/F=Semifinals E/F; R=Repechage
Sailing
Slovenian sailors have qualified one boat for each of the following events. ;Men ;Women ;Open M = Medal race; OCS = On course side of the starting line; DSQ = Disqualified; DNF = Did not finish; DNS= Did not start; RDG = Redress given
Shooting
One Slovenian shooter qualified to compete in the following events: ;Men
Swimming
Slovenian swimmers earned qualifying standards in the following events : ;Men ;Women
Tennis
Slovenia nominated four female tennis players to compete in the tournament.
