"Girlfriend" is a song by Canadian singer-songwriter Avril Lavigne. The song was written by Lavigne and Dr. Luke; the latter is also the producer. "Girlfriend" was released as the lead single from her third studio album, The Best Damn Thing (2007) on February 27, 2007 by Columbia and RCA Records. Lyrically, the song revolves around its protagonist having a crush on someone who is in a relationship, proclaiming she should be his girlfriend.

Avril Ramona Lavigne is a Canadian singer-songwriter. She is considered a key musician in the development of pop-punk music, as she paved the way for female-driven, punk-influenced pop music in the early 2000s. Her accolades include eight Grammy Award nominations, among others.