Avril Ramona Lavigne was born in Belleville, Ontario to a French-born father, John, and a Franco-Ontarian mother, Judy. Both parents are Roman Catholic. Avril's musical talent was first spotted at the age of two when her mother says Avril began singing along with her on church songs. At age five she moved with her family to Napanee, Ontario, where she sang in a church choir and taught herself to play the guitar.

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.

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, Avril was spotted by local folk singer Steve Medd (a relation of the influential Canadian journalist, Ben Medd), who invited her to sing on his song "Touch The Sky" for his 1999 album Quinte Spirit. She also sang on "Temple Of Life" and "Two Rivers" for his follow up album, My Window To You, in 2000.

At the age of sixteen she was signed by Ken Krongard, the artists-and-repertoire A&R representative of Arista Records, who invited the head of Arista, Antonio "L.A." Reid, to hear her sing in a New York City studio. She then completed work on her first album. Avril is extremely close to her younger sister Michelle Lavigne and her older brother Matthew Lavigne. Michelle is two years younger than Avril while Matt (Matthew) is three years older than Avril. On July 15, 2006, Avril married Deryck Whibley, the lead singer of Canadian punk band Sum 41.