Gwen Renée Stefani is born in Fullerton, California, to Dennis Stefani, an Italian American Yamaha marketing executive, and Patti Flynn, an Irish American accountant. She grew up in Anaheim, California.

Growing up, Gwen was exposed to a diverse range of music, including ska, new wave, and pop. Her older brother, Eric, introduced her to bands like Madness and The Selecter, which would heavily influence her future musical style.

During high school, Gwen participated in various musical activities, including singing and performing in school productions. This period helped her hone her vocal skills and stage presence.

Gwen's brother Eric, a founding member, invites her to join his ska band, No Doubt. Initially, she provides backing vocals, but her role quickly evolves into that of the lead singer.