In 2004, Stefani wrote and recorded her first solo album Love. Angel. Music. Baby. The album contained pop music and dance tracks, and included hip hop and R&B-influences. Its third single "Hollaback Girl" became the first U.S. digital single to exceed sales of one million.

Stefani is currently recording with No Doubt on an album that's expected to be released sometime in 2007. She married Bush frontman Gavin Rossdale in 2002 and gave birth to a son, Kingston, in 2006.

Stefani was born in Fullerton, California, but grew up in Anaheim. Her father, Dennis Stefani, is Italian American, and her mother Patti Flynn is of Irish and Scottish descent. She has a sister, Jill, and two brothers, Eric and Todd. Jill appeared in No Doubt's "Just a Girl" music video. Stefani attended California State University, Fullerton, and Loara High School (class of 1987), where she was on the swim team. Her first job was scrubbing floors at a Dairy Queen, and she once worked at the makeup counter of a department store. Her brother Eric was the keyboardist for No Doubt, but eventually left the band to pursue a career in animation on The Simpsons. Other members of the group include Tom Dumont, Tony Kanal, and drummer Adrian Young.

The band's third album Tragic Kingdom, which followed their eponymous debut No Doubt (1992) and The Beacon Street Collection (1995), took three years to make. During this time, the band almost split up due to the break up of Kanal and Stefani. However, this was to become a major inspiration for Stefani lyrically. The album, released in 1995, was certified diamond in the US for shipping over 10 million copies and sold over 14 million copies worldwide. Following the success of Tragic Kingdom, Stefani became highly popular and recognizable. The tension this produced with the other members of the band was touched upon in their video for the song "Don't Speak". Stefani met Bush and now Institute frontman Gavin Rossdale in 1995 at a concert in which she was performing to promote Tragic Kingdom. The release of The Singles 1992-2003, a CD with the band's best hits, and Everything in Time: B-sides, Remixes and Rarities prompted media speculation about a break-up, which the band denied in later interviews.

Outside of No Doubt Stefani has collaborated with other artists, most notably for the singles "South Side" and "Let Me Blow Ya Mind" with Moby and Eve respectively. In 2002, Eve and Stefani won a Grammy Award for Best Rap/Sung Collaboration for "Let Me Blow Ya Mind."

Stefani's debut solo album Love. Angel. Music. Baby. was released in November 2004 across the world. The album made its debut on the U.S. Billboard 200 albums chart at number seven, selling more than 310,000 copies in its first week. In early 2005 it reached a peak position of number five in the U.S. and number three in Canada. Love. Angel. Music. Baby. topped the albums chart in Australia. Unexpected success came in Mexico for Love.Angel.Music.Baby., as 4 of the 6 singles released for the album reached the top 10: "Cool" and "Hollaback Girl" peaked at 1, while "What You Waiting For" and "Rich Girl" peaked at 9 and 8, repectively. Remixes of the songs maintained the singles on the Mexican charts until March 2006 when after more than half a year of sales and airplay, "Hollaback Girl" exited the Mexican Top 100. The album itself peaked at number 2, and was the highest selling English album in the country for over a month.

Stefani collaborated with singer-songwriter Linda Perry of 4 Non Blondes on the album, along with The Neptunes, OutKast's André 3000, and Dallas Austin among others. The first single released from the album was "What You Waiting For?", which was a top twenty success in Asia and Europe.

"Rich Girl" was released as the album's second single from the album; a duet with rapper Eve, and produced by Dr. Dre, it is an adaptation of a 1990s pop song by British musicians Louchie Lou and Michie, which itself is a cover of "If I Were a Rich Man", from the musical Fiddler on the Roof, written by Jerry Bock and Sheldon Harnick. "Rich Girl" proved successful on several formats, and reached the UK and U.S. top ten. Love. Angel. Music. Baby.'s third single "Hollaback Girl" became Stefani's first U.S. and second Australian number-one single; it peaked at number eight in the UK and at number twelve in Canada. The song was the first U.S. digital download to sell more than one million copies legally, and its brass-driven composition remained popular throughout 2005. Its lyrical content features the word "shit" thirty-seven times. Maxim magazine voted it the most annoying song of all time.

The fourth single "Cool" was released shortly following the success of its predecessor, but failed to match its chart success, reaching the U.S. and the UK top twenty. However, "Cool" was Stefani's first Canadian number-one single. The song's music video, filmed in Lake Como, Italy, depicts Stefani's former relationship with No Doubt bass guitarist Tony Kanal, and it received strong rotation on Canada's MuchMusic. "Luxurious" was released as the album's fifth single, but did not perform as well as its predecessors.

"Crash" was released as the album's sixth single in early 2006 in lieu of the production of Love. Angel. Music. Baby. sequel, which Stefani postponed because of her pregnancy.

Stefani received five Grammy Award nominations on December 8, 2005. She was nominated in five categories: "Album of the Year", "Best Female Pop Vocal Performance", "Best Pop Vocal Album", "Record of the Year" and "Best Rap/Sung Collaboration".

The release of her solo album has also brought attention to Stefani's entourage of four Harajuku Girls. Named Love, Angel, Music, and Baby by Stefani, the Harajuku girls are named for the area around the Harajuku Station of Tokyo, Japan, known as a popular shopping destination and fashion center for teenagers. Following the style of their namesake area, Stefani's Harajuku girls are usually flamboyantly dressed (sometimes in a somewhat "Gothic Lolita" style). They have been featured in her music videos and press coverage and on the album cover for Love. Angel. Music. Baby., and have a song dedicated to them on the album. However, Stefani's adoption of this component of Japanese culture drew criticism from Mihi Ahn at Salon.com, and others who feel that Stefani has stripped Japanese street fashion of its authenticity and created yet another example of the 'submissive Asian female' stereotype. Wrote Ahn, "Stefani has taken the idea of Japanese street fashion and turned these women into modern-day geisha, contractually obligated to speak only Japanese in public, even though it's rumored they're just plain old Americans and their English is just fine... she's swallowed a subversive youth culture in Japan and barfed up another image of submissive giggling Asian women. "

According to the Jan/Feb 2006 edition of Blender magazine, stand-up comic Margaret Cho has labeled the Harajuku Girls as a "minstrel show" that reinforces ethnic stereotypes of Asian women.

A follow up album containing leftover songs from L.A.M.B and some new songs entitled "Candyland" is expected to be released towards the end of the year along with a DVD of Stefani's first solo tour. "Candyland" is expected to include the songs "Wind it Up" and "Orange County Girl," which Gwen first exhibited during her 2005 Harajuku Lovers tour.

"Candyland" is also expected to contain the songs, "Breakup", "Flourescent Lights", and "Candyland".

Gwen has also returned to the studio with No Doubt, and a new album is expected to be released in the Spring of 2007.

Stefani met Bush and now Institute frontman Gavin Rossdale in 1995 at a concert in which she was performing to promote Tragic Kingdom. On September 14, 2002 Stefani and Rossdale married, and they have homes in California and the Primrose Hill district of London .