According to Pausanias, the games were reestablished (from mythical times) to celebrate the peace treaty among three kings, Iphitos, Lycourgos, and Kleosthenes. This peace, later known as the Sacred Truce, was remembered and honoured during each Olympic festival. Those who broke this truce were fined and often banned from the games and refused oracles by Delphi.

During the height of the prestige of Olympia, events and basic chronology were dated by the Olympiads, which were in turn named after the winner of the foot race. The first Olympic festival was titled the Koroibos Olympiad after the first winner. The Eleans maintained a list (doubted by some, such as Plutarch) which recorded all of the winners of all of the competitions ever held. The three Olympiads conducted by Pisa as well as the Olympiad organized by Nero were not recorded by the Eleans and were considered "non-Olympiads." The games took place every four years. The exact time of the games is not known, but they were held during the summer and during a full moon, probably in the hot months of July or September.

The Olympian Senate (all from Elis) met in the Bouleuterion and controlled both the revenue and officials of the games. The priests and magistrates lived in the Prytaneion while the high priests lived in the Theokoleon..