Déjanire is an opera (tragédie lyrique) in 4 acts composed by Camille Saint-Saëns to a libretto in French by Louis Gallet and Camille Saint-Saëns. The last of Saint-Saëns' operas, it premiered on 28 August 1898 in the new arènes in Beziers. One of the opera's central characters, Hercule (Hercules), had been the subject of two earlier symphonic poems by Saint-Saëns – Le Rouet d'Omphale (1872) and La Jeunesse d'Hercule (1877). The story is based on The Trachiniae by Sophocles (also the source for Handel's opera Hercules).