"The Boxer" is a song written by Paul Simon and recorded by the American music duo Simon & Garfunkel from their fifth studio album, Bridge over Troubled Water (1970). Produced by the duo and Roy Halee, it was released as a standalone single on March 21, 1969, but included on the album nine months later (at the time, songs that had been released this far ahead were rarely included on the next studio album). The song is a folk rock ballad that variously takes the form of a first-person lament as well as a third-person sketch of a boxer. The lyrics are largely autobiographical and partially inspired by the Bible, and were written during a time when Simon felt he was being unfairly criticized. The song's lyrics discuss poverty and loneliness. It is particularly known for its plaintive refrain, in which they sing 'lie-la-lie', accompanied by a heavily reverbed snare drum.

"The Boxer" was the follow-up to one of the duo's most successful singles, "Mrs. Robinson". It peaked at No. 7 on the Billboard Hot 100. It performed well internationally, charting within the Top 10 in nine countries, peaking highest in the Netherlands, Austria, South Africa, and Canada. Rolling Stone ranked the song No. 106 on its list of the 500 Greatest Songs of All Time.