"Once Upon a Dream" is a song written for the 1959 animated musical fantasy film Sleeping Beauty produced by Walt Disney. Its lyrics were written by Jack Lawrence and Sammy Fain while the music is adapted by George Bruns. The song's melody is based on the "Grande valse villageoise" (nicknamed "The Garland Waltz"), from the 1890 ballet The Sleeping Beauty by Pyotr Ilyich Tchaikovsky.

"Once Upon a Dream" serves as the film's main theme, and as the love theme of Princess Aurora and Prince Phillip. It is performed in the film by a chorus as an overture and third-reprise finale, as well by Mary Costa and Bill Shirley, who voiced the roles of Aurora and Phillip,