"Underneath It All" is a pop song written by Gwen Stefani and Dave Stewart for No Doubt's fourth album Rock Steady (2001). The song features reggae production and guest vocals from deejay Lady Saw. It received mixed reviews from pop music critics.

"Underneath It All" was released as the album's third single in mid-2002 (see 2002 in music). It became No Doubt's highest charting American single but was less successful elsewhere. The song won a Grammy Award for Best Pop Performance by a Duo or Group with Vocal at the 46th Grammy Awards.