“Mr. Brightside” is the debut single by American rock band The Killers. The song is featured on the group’s debut studio album Hot Fuss and was written by Brandon Flowers and Dave Keuning.
Lyrically, “Mr. BrightSide” depicts the jealousy and paranoia of a man who suspects his significant other is deliberately cheating on him. The song is inspired by an unfaithful ex-girlfriend of frontman Brandon Flowers. Dave Keuning composed the song’s verses before meeting Flowers. Flowers then wrote lyrics and composed the chorus after hearing Keuning’s ideas. In November 2001, the group had recorded “Mr. Brightside” along with three other demos including “Desperate”, “Replaceable”, and “Under the Gun” at Mike Sak’s Kill the Messenger Studio in Henderson, Nevada. They handed out a demo of the song for free during their shows in 2002.