"Billionaire" is a song by American rapper Travie McCoy from his debut studio album, Lazarus (2010), featuring vocals by American singer-songwriter Bruno Mars. It was first released on March 9, 2010, in various countries via digital download as the album's lead single by Fueled by Ramen. McCoy co-wrote the song with its producers Mars, Philip Lawrence and Ari Levine of the Smeezingtons. The song was created from a melody hummed by Mars and Lawrence. The lyrics were written during an eleven-day trip Mars and Levine made to London to work on a record, supported by Mars's label.

Travis Lazarus "Travie" McCoy is an American rapper, singer, and songwriter. He is the co-founder and lead vocalist of the rap rock band Gym Class Heroes, in addition to having a solo career. McCoy became involved with punk rock scenes as a teenager. He formed the band Gym Class Heroes with childhood friend Matt McGinley; after several line-up changes, the group was signed to Fueled by Ramen, which released their debut album.