"Complicated" is a song by Canadian singer-songwriter Avril Lavigne from her debut album, Let Go (2002). The ballad was released as her debut single and the lead single from the album on 11 March 2002 by Arista Records.
Lavigne and production team the Matrix (Lauren Christy, Scott Spock, and Graham Edwards) are credited as writers, although the extent of Lavigne's contributions have been publicly disputed by both parties. Production on the song was helmed solely by the Matrix. According to Lavigne, the song is about being honest with oneself rather than "putting on a face".
"Complicated" received positive reviews from music critics, who praised the song as infectious pop rock. Some reviewers, however, felt that the song was inauthentic and that Lavigne was a poseur.
"Complicated" peaked at number two on the Billboard Hot 100, ultimately selling 1.1 million copies in the US. The song also spent a consecutive sixteen weeks at number one on the Billboard Adult Top 40 chart, breaking a previous record held by Natalie Imbruglia's "Torn".