"Serious" is a song by American singer Gwen Stefani for her debut solo studio album, Love. Angel. Music. Baby. (2004). It was released on November 12, 2004, along with the rest of the aforementioned album by Interscope Records. The track was written by Stefani and her No Doubt bandmate, Tony Kanal. The latter also produced the song with Mark "Spike" Stent, who Stefani and Kanal previously worked with on No Doubt's fifth studio album, Rock Steady (2001). "Serious" is a synth-pop song with lyrics pertaining to a strong romantic interest in a significant other.