"Mr. Brightside" is the debut single of American rock band the Killers. It is taken from their debut studio album, Hot Fuss (2004). Written by band members Brandon Flowers and Dave Keuning, it was one of the first songs the Killers ever wrote. Two music videos were made for the song: the first one was shot in black and white and features the band performing in an empty room and the second one was based on the 2001 film Moulin Rouge!.

The Killers are an American rock band formed in Las Vegas in 2001 by Brandon Flowers and Dave Keuning. After going through a number of short-term bass players and drummers in their early days, both Mark Stoermer and Ronnie Vannucci Jr. joined the band in 2002. The band's name is derived from a logo on the bass drum of a fictitious band portrayed in the music video for the New Order song "Crystal".