"Dark Horse" is a song by American singer Katy Perry featuring rapper Juicy J. It was originally released on September 17, 2013, by Capitol Records as the first promotional single from Perry's fourth studio album, Prism (2013).
Three months later, it was released as the third official single on December 17. Both artists co-wrote the song with its producers, Max Martin, Cirkut, and Dr. Luke, alongside Sarah Hudson. It was conceived by Perry and Hudson during a writing session in Perry's hometown of Santa Barbara, California, and Juicy J was later commissioned for a verse on the song.
"Dark Horse" combines the genres of pop, trap, and hip hop, replicating what has been described as a "Southern rap-techno mashup". The track features a minimal production, with a "seductive" and "mature" tone to Perry's vocals, while Juicy J is featured on the song's intro and rapped bridge.
Perry, in interviews, said she wanted the song to have a "witchy, spell-y kind of black magic-y idea", so she wrote it from the perspective of a witch warning a man not to fall in love with her because if he does, she will be his last. The song was part of a competition sponsored by Pepsi in which fans could vote via Twitter on whether they would prefer either "Dark Horse" or "Walking on Air" to be released as the first promotional single from Prism.
"Dark Horse" was a commercial success, charting at number one in Canada, the Netherlands and the United States. It also reached the top ten in almost 20 countries including New Zealand, United Kingdom, Sweden and Venezuela as well as the Digital Songs chart of Billboard magazine.
Billboard identified Dark Horse as cementing trap music's place on the charts. Perry first performed the song live at the 2013 iHeartRadio Music Festival in Las Vegas on September 20, 2013. The song's first major television performance was at the 56th Annual Grammy Awards on January 26, 2014.
"Dark Horse" was nominated for Best Pop Duo/Group Performance at the 57th Annual Grammy Awards. The song has sold 13.2 million units (combined sales and track-equivalent streams), becoming the second best-selling song worldwide for 2014.
In 2014, Flame, a Christian rap artist, filed a copyright infringement lawsuit against Perry and the other songwriters, claiming that "Dark Horse" copied from his 2008 song "Joyful Noise". On July 29, 2019, a federal jury ruled in favor of Flame and the co-plaintiffs Da' T.R.U.T.H. and Chike Ojukwu.
The jury ordered Perry, her collaborators, and associated labels to pay $2.78 million in damages.
Of this, Perry was ordered to pay $550,000.