Gwen Renée Stefani was born and raised in Anaheim, California, the second oldest of 4 children. Stefani begain to take interest in musicals such as The Sound of Music and Evita, and after making a demo tape for her father, she was encouraged to take music lessons to train her "loopy, unpredictable" voice. Stefani made her onstage debut during a talent show at Loara High School, where she sang "I Have Confidence," from The Sound of Music, in a self made tweed dress inspired by one from the film. After graduating from high school in 1987, she began attending California State University, Fullerton.
Older brother Eric introduced Stefani to 2 Tone music by Madness and The Selecter, and invited her to provide vocals for No Doubt, a ska band he was forming. Finally, in 1991, the band was signed to Interscope Records, and in 1992, released a self titled debut album in 1992. However, problems were rife in that the ska-pop combination offered by No Doubt was swamped by the popularity of grunge, and in the 3 years to self released second album “The Beacon Street Collection” (1995) and third album “Tragic Kingdom” (also 1995), No Doubt almost split due to the failed romantic relationship between Stefani and bandmate Tony Kanal. 5 singles were released from “Tragic Kingdom”, with "Don't Speak" leading the 1996 U.S. year end airplay chart, and the album itself has sold more than 16 million copies worldwide, and received several Grammy Award nominations.
No Doubt released the less popular “Return of Saturn” in 2000, and the band's 2001 album, “Rock Steady”, achieved career high singles chart positions in the U.S., with singles "Hey Baby" and "Underneath It All" receiving Grammy Awards. A greatest hits collection, “The Singles 1992–2003”, including a cover of Talk Talk's "It's My Life", was released in 2003.

Outside No Doubt, Stefani has provided backup vocals for Sublime on the song "Saw Red", and collaborated on the singles "South Side" with Moby and "Let Me Blow Ya Mind" with Eve (for which they won a 2002 Grammy Award for Best Rap/Sung Collaboration). Stefani's debut solo album “Love. Angel. Music. Baby.” was released in November 2004, and debuted at number 7 on the U.S. Billboard 200, selling 309,000 copies in its first week. First single “What You Waiting For?” charted outside the U.S. Top 40, but reached the Top 10 on most other charts. Second single “Rich Girl”, a duet with rapper Eve, produced by Dr. Dre and an adaptation of a 1990s song by Louchie Lou and Michie One (which itself is a cover of "If I Were a Rich Man", from the musical Fiddler on the Roof), reached both the U.S. and the UK Top 10. "Hollaback Girl" became Stefani's first U.S. and second Australian number 1 single, and was the first U.S. digital download to sell more than 1 million copies legally. Fourth single “Cool” climbed into the U.S. and UK Top 20, but fifth offering "Luxurious" was less successful. “Love. Angel. Music. Baby.” achieved multi platinum status in the U.S., UK, Australia and Canada, has sold over 7 million copies, and led to a 2005 Grammy Award nomination for Best Female Pop Vocal Performance, and 5 2006 Grammy Award nominations for Record of the Year, Album of the Year, Best Female Pop Vocal Performance, Best Pop Vocal Album, and Best Rap/Sung Collaboration.

Stefani's second solo album, “The Sweet Escape”, released in December 2006, included collaborations with Akon and Keane’s Tim Rice-Oxley. "Wind It Up", the album's lead single, reached the Top 20 in most markets, but the title track earned Stefani a Grammy nomination, and is the most successful song of her solo career. "4 In The Morning", the third single, met with moderate success, but fourth single, a hybird version of “Now That You Got It” (which featured Damian Marley) was Stefani's first solo single to fail to chart on the Billboard Hot 100.

Stefani made most of the clothing that she wore on stage with No Doubt, and eventually launched a fashion line named L.A.M.B. in 2004, which takes influence from a variety of fashions, including Guatemalan, Japanese, and Jamaican, and has achieved popularity among celebrities, being worn by Teri Hatcher, Nicole Kidman, and Stefani herself. Stefani also made her acting debut playing Jean Harlow in Martin Scorsese's “The Aviator” in 2004, and was nominated for the Screen Actors Guild Awards for Outstanding Performance by Cast in Motion Picture.

Gwen Stefani has sold more than 30 million albums worldwide.