"What You Waiting For?" is a song by American singer Gwen Stefani from her debut solo studio album, Love. Angel. Music. Baby. (2004). Written by Stefani and Linda Perry, the song is the album's opening track and was released as Stefani's debut solo single. Lyrically, "What You Waiting For?" details Stefani's lack of inspiration and fear of producing the album, as well as her reaction to pressures exerted by her record label. It is primarily an electropop song and introduces Stefani's four backup dancers, the Harajuku Girls, who had a major input into the album's production.

Gwen Renée Stefani is an American singer and songwriter. She is a co-founder, lead vocalist, and the primary songwriter of the band No Doubt, whose singles include "Just a Girl", "Spiderwebs", and "Don't Speak", from their 1995 breakthrough studio album Tragic Kingdom, as well as "Hey Baby" and "It's My Life" from later albums.