Le poisson rêveur (The Dreamy Fish) is an unfinished tone poem for solo piano composed between 1900 and 1901 by Erik Satie, based on a tale by "Lord Cheminot". The text does not survive and Satie's music went unpublished for decades. In performance the piece lasts about 6 minutes.

Eric Alfred Leslie Satie, who signed his name Erik Satie after 1884, was a French composer and pianist. He was the son of a French father and a British mother. He studied at the Paris Conservatoire, but was an undistinguished student and obtained no diploma. In the 1880s he worked as a pianist in café-cabaret in Montmartre, Paris, and began composing works, mostly for solo piano, such as his Gymnopédies and Gnossiennes. He also wrote music for a Rosicrucian sect to which he was briefly attached.