"Rainbow" is a song by Australian singer Sia, released on 15 September 2017 as the lead single from the animated film My Little Pony: The Movie soundtrack.

In the film, the song is performed by a pop singer pegasus named Songbird Serenade (voiced by Sia).

[3] The video cuts between footage of Songbird Serenade performing for a large crowd and Ziegler dancing only on a stage covered by a thin strip of water, wearing a wig resembling Songbird Serenade's mane, and successfully fighting and conquering the elements.

Bryan Rolli from Billboard called the song "uplifting", explaining "The Australian pop star eschews the vocal acrobatics of past hits like 'Chandelier' in favor of a restrained hook and hypnotic beat, while still sounding as powerful and inspired as ever.

'"[6] Hilary Hughes from MTV said, "'Rainbow' has all the hallmarks of a stellar Sia single: Empowering message, driving beat, and an infectiously catchy melody.