"Smile" is a song by Canadian recording artist Avril Lavigne from her fourth studio album Goodbye Lullaby (2011). It was co-written by Lavigne, Max Martin and Shellback and produced by Martin and Shellback. "Smile" was released on 11 April 2011 by RCA Records as the second single from the album to Australian radio stations and then on 17 May the song was released to US contemporary hit radio. Upon its release, the song received critical acclaim from music critics, who described the track as a "sassy and catchy pop song". It has charted inside the top-thirty on the Australian, Japanese and New Zealand charts, in addition to being certified by the recording industry associations of Australia and the United States. A music video directed by Shane Drake was filmed in April 2011 and released on 20 May. By November 2014, the music video had reached 100 million views on Vevo.

Goodbye Lullaby is the fourth studio album by Canadian singer-songwriter Avril Lavigne. It was released worldwide on March 8, 2011 through RCA Records. Recording sessions for the album began in November 2008 and continued over a period of nearly two years, concluding in October 2010. Goodbye Lullaby is a primarily a pop rock album and is considered a more introspective record from Lavigne in comparison to her previous material, consisting mainly of stripped down instruments such as the piano and acoustic guitar. Lavigne assumed an integral role in the album's production and co-wrote every original track on Goodbye Lullaby, as well as collaborating with several producers including Max Martin, Shellback, Butch Walker, and her ex-husband Deryck Whibley. Goodbye Lullaby is Lavigne's third and final studio album with RCA, following The Best Damn Thing (2007) and Under My Skin (2004)