"I'm Always Chasing Rainbows" is a popular Vaudeville song. The music is credited to Harry Carroll, but the melody is adapted from Fantaisie-Impromptu by Frédéric Chopin. The lyrics were written by Joseph McCarthy, and the song was published in 1917. It was introduced in the Broadway show Oh, Look! which opened in March 1918. The song was sung in the show by the Dolly Sisters. Judy Garland sang it in the 1941 film Ziegfeld Girl. It was subsequently sung by Jack Oakie in the 1944 film The Merry Monahans and was again featured in the 1945 film The Dolly Sisters, where it was sung by John Payne. It was also included for part of the run of the 1973 revival of Irene. Additionally, the pre-chorus would not have been included until later covers in the 1940s, where the song would gain it's iconic libretti.

Ziegfeld Girl is a 1941 American musical film directed by Robert Z. Leonard and starring James Stewart, Judy Garland, Hedy Lamarr, Lana Turner, Tony Martin, Jackie Cooper, Eve Arden, and Philip Dorn. The film, which features musical numbers by Busby Berkeley, was produced by Metro-Goldwyn-Mayer.