The 2004 Summer Olympics, officially known as the Games of the XXVIII Olympiad and commonly known as Athens 2004, was an international multi-sport event held from 13 to 29 August 2004 in Athens, Greece. The Games saw 10,625 athletes compete, some 600 more than expected, accompanied by 5,501 team officials from 201 countries. There were 301 medal events in 28 different sports. Athens 2004 marked the first time since the 1996 Summer Olympics that all countries with a National Olympic Committee were in attendance, and also saw the return of the Olympic Games to the city where they began. Having previously hosted the first modern Olympics in 1896, Athens became one of only four cities at the time to have hosted the Summer Olympic Games on two occasions.
A new medal obverse was introduced at these Games, replacing the design by Giuseppe Cassioli that had been used since 1928. The new design features the Panathenaic Stadium in Athens. This rectified the long-running mistake of using a depiction of the Roman Colosseum rather than a Greek venue.