L'Olimpiade is an opera libretto in three acts by Metastasio originally written for an operatic setting by Antonio Caldara of 1733. Metastasio’s plot vaguely draws upon the narrative of "The Trial of the Suitors" provided from Book 6 of The Histories of Herodotus, which had previously been the base for Apostolo Zeno's libretto Gli inganni felici (1695). The story, set in Ancient Greece at the time of the Olympic Games, is about amorous rivalry and characters' taking places to gain the loved one. The story ends with the announcement of two marriages.
Metastasio, as Imperial court poet at the court of Vienna, was requested to write the libretto to help celebrate the birthday of Empress Elisabeth Christine of Brunswick-Wolfenbüttel in 1733. The court composer Caldara was assigned to compose the music. The libretto attracted attention immediately and productions were soon amounted across Europe. Metastasio himself commented to Saverio Mattei that L’Olimpiade had been "performed and repeated in all the theatres of Europe". Indeed, it ranks with Demofoonte and Didone abbandonata, dramas excelled in popularity only by Artaserse and Alessandro nell'Indie. The popularity of L’olimpiade may subsequently have prompted Metastasio’s La Nitteti, a twin drama in several respects.
Megacles arrives in Sicyon just in time to enter the Olympic Games under the name of Lycidas, a friend who once saved his life. Unknown to Megacles, Lycidas is in love with Aristaea, whose hand is to be offered to the winner of the games by her father, King Cleisthenes. Lycidas, once betrothed to Princess Argene of Crete, is unaware that Megacles and Aristaea already love each other, and he subsequently tells his friend of the prize. Aristaea and Megacles greet each other fondly, but Megacles now feels bound by his promise to compete as Lycidas. Meanwhile, Argene arrives in Olympia disguised as a shepherdess, to win back Lycidas.