Amadis de Gaule, or Amadis des Gaules, is a French opera in three acts by the German composer Johann Christian Bach. The libretto is a revision by Alphonse de Vismes of Amadis by Philippe Quinault, originally set by Jean-Baptiste Lully in 1684, which in turn, was based on the knight-errantry romance Amadis de Gaula (1508). Bach's opera was first performed at the Académie Royale de Musique, Paris, on 14 December 1779. It followed the contemporary French fashion for resetting libretti by Quinault. The work was not a success with the Parisian public, mainly because it pleased neither the supporters of Gluck nor those of Piccinni, the two leading rival opera composers in France at the time. It was the last opera J. C. Bach composed.

Amadis or Amadis de Gaule is a tragédie en musique in a prologue and five acts by Jean-Baptiste Lully to a libretto by Philippe Quinault based on Nicolas Herberay des Essarts' adaptation of Garci Rodríguez de Montalvo's Amadis de Gaula. It was premiered by the Paris Opera at the Théâtre du Palais-Royal sometime from January 15 to 18, 1684. There was a later production at Versailles without scenery or machines in 1685.