Avril Ramona Lavigne was born in Belleville, Ontario, Canada, the daughter of Judith-Rosanne "Judy" (née Loshaw) and Jean-Claude Lavigne. Lavigne's father is of French Canadian descent, and named her Avril after the month "April" in French.
In 1998, Lavigne won a competition to sing with fellow Canadian singer Shania Twain on her first major concert tour. She appeared alongside Twain at her concert in Ottawa, appearing on stage to sing "What Made You Say That". She was discovered by her first professional manager, Cliff Fabri, while singing country covers at a Chapters bookstore in Kingston, Ontario. During a performance with the Lennox Community Theatre, Lavigne was spotted by local folk singer Steve Medd, who invited her to contribute vocals on his song, "Touch the Sky", for his 1999 album, Quinte Spirit. She later sang on "Temple of Life" and "Two Rivers" for his follow up 2000 album, My Window to You.
Because her songs have evolved, covering a variety of styles of music, Lavigne is not easily defined by only a few genres. Her music has been described as rock, pop rock, alternative rock, pop, pop punk, alternative pop, post-grunge, teen pop, and powerpop.
Lavigne released her debut album, Let Go, on June 4, 2002 in the United States, where it reached number two. It peaked at number one in Australia, Canada and the United Kingdom. This made Lavigne, at 17, the youngest female soloist to have a number-one album in the United Kingdom until that time. By the end of 2002, the album was certified four-times platinum by the RIAA, making her the best-selling female artist of 2002 and Let Go as the top-selling debut of the year. By May 2003, Let Go had accumulated over 1,000,000 sales in Canada, receiving a diamond certification from the Canadian Recording Industry Association. As of 2009, the album has sold over 16 million units worldwide. RIAA has certified the album six-times platinum, denoting shipments of over six million units in the US.
Lavigne's debut single and the album's lead single, "Complicated", went to number one in Australia and number two in the United States. "Complicated" was one of the best-selling Canadian singles of 2002. "Complicated" was also featured on the teen television show, Dawson's Creek. Subsequent singles "Sk8er Boi" and "I'm With You" reached the top ten in the United States. Thanks to the big success of her first three singles, Lavigne was the second artist in history to have three #1 songs from a debut album on the Billboard Mainstream Top 40. Lavigne was named Best New Artist at the 2002 MTV Video Music Awards, won four Juno Awards in 2003 out of six nominations, received a World Music Award for "World's Best-Selling Canadian Singer", and was nominated for eight Grammy Awards, including Best New Artist and Song of the Year for "Complicated" (2003) and "I'm With You" (2004).
Lavigne had a cameo in the film Going the Distance and also appeared in an episode of Sabrina, the Teenage Witch, performing "Sk8er Boi" with her band, but her feature film debut was in the 2006 animated film Over the Hedge, which is based on the comic strip of same name. She voiced the character Heather, a Virginia Opossum.
Lavigne acted in the Richard Gere film The Flock, as the girlfriend of a crime suspect, and also appeared in the film Fast Food Nation, based on the book Fast Food Nation: The Dark Side of the All-American Meal.
In August 2006, Canadian Business magazine ranked her the seventh top Canadian actor dominating in Hollywood in their second-annual ranking Celebrity Power List. She is ranked second with the most web hits, and sixth in TV mentions.
Lavigne has a star tattooed on the inside of her left wrist that matches the style of the one used for her first album artwork. It was created at the same time as friend and musical associate Ben Moody's identical tattoo. In late 2004, she had a small pink heart-shaped tattoo featuring the letter 'D' applied to her right wrist, which represents her now separated husband Deryck Whibley, a fellow Canadian singer who is the lead singer/guitarist of punk band Sum 41. They began dating in February 2004 and on 27 June 2005, Lavigne and Whibley became engaged. Whibley proposed to Lavigne by surprising her with a trip to Venice, a gondola ride, and then a romantic picnic.
The couple married in a Catholic ceremony attended by about 110 guests on 15 July 2006, at a private estate in Montecito, California. When asked if they were ready for kids the couple said "not right now but somewhere down the road".
It was announced on 17 September 2009, that Lavigne and Whibley had split up and that divorce papers would soon follow. On 9 October 2009, Lavigne filed for divorce.