Naïs is an opera by Jean-Philippe Rameau first performed on 22 April 1749 at the Opéra in Paris. It takes the form of a pastorale héroïque in three acts and a prologue. The librettist was Louis de Cahusac, in the fourth collaboration between him and Rameau. The work bears the subtitle Opéra pour La Paix, which refers to the fact that Rameau composed the opera on the occasion of the Treaty of Aix-la-Chapelle, at the conclusion of the War of the Austrian Succession. Its original title was Le triomphe de la paix, but criticism of the terms of the treaty led to a change in the title.