"Smile" is a song based on the theme song used in the soundtrack for Charlie Chaplin's 1936 film Modern Times.

Chaplin, who composed the song with the help of composer David Raksin, was inspired by a sequence in the first act love duet from Puccini's opera Tosca, beginning with Cavaradossi singing "Quale occhio al mondo può star di paro". John Turner and Geoffrey Parsons added the lyrics and title in 1954. In the lyrics, based on lines and themes from the film, the singer is telling the listener to cheer up and that there is always a bright tomorrow, just as long as they smile.

"Smile" has become a popular standard since its original use in Chaplin's film and has been recorded by numerous artists.

Nat King Cole recorded the first version with lyrics. It charted in 1954, reaching number 10 on the Billboard charts and number 2 on the UK Singles Chart. This version was also used at the beginning of the 1975 movie Smile.

Sammy Davis Jr. recorded a cover version of the Cole original, as part of his tribute album The Nat King Cole Songbook in 1965.

American singer Michael Jackson recorded "Smile" for HIStory: Past, Present and Future, Book I (1995). It was scheduled to be released as the final single from the album in 1997, but was withdrawn before its intended commercial release and was only released promotionally in limited quantities. It is performed in the Michael Jackson: One Las Vegas production.

Entertainment Weekly called Jackson's version of the song a "destined-for-Disney rendition." James Hunter of Rolling Stone wrote a negative review: "the climactic version of Charlie Chaplin's "Smile" has zero point of view on itself; its blend of rampaging ego and static orchestral pop is a Streisand-size mistake."

Jackson considered the original "Smile" to be one of his favorite songs. In 2009 at Jackson's memorial service, his brother Jermaine Jackson sang a version of the song in Michael's honor.