"The One That Got Away" is a song by American singer Katy Perry for her third studio album, Teenage Dream (2010). The song was produced by Dr. Luke and Max Martin, both of whom also co-wrote the song with Perry. The song is a mid-tempo pop ballad about a lost love. It features references to the rock band Radiohead as well as the relationship of Johnny Cash and June Carter Cash to express the strength of the relationship. The song was released in October 2011 by Capitol Records as the album's sixth and final single.

"The One That Got Away" peaked at number three on Billboard Hot 100, with Teenage Dream becoming the seventh album in the 53-year history of the Hot 100 to generate at least six top 10s. The single reached the top of the Billboard Hot Dance Club Songs, Adult Top 40, and Mainstream Top 40 charts.

The accompanying music video for the song was directed by Floria Sigismondi and premiered in November 2011, featuring actor Diego Luna. An official remix featuring rapper B.o.B was released to digital retailers on December 20, 2011. An official acoustic rendition was released to digital retailers on January 16, 2012, this version was included in Teenage Dream: The Complete Confection edition. The song has been covered by several artists, including Richard Marx, Jordan Pruitt, and Selena Gomez & the Scene.

On September 13, 2011, at the New York City's Irving Plaza, Capitol Records confirmed to Billboard that "The One That Got Away" would be the sixth single from Teenage Dream. Perry said in a statement from the label:

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