"Best Friend" is a song by American rapper 50 Cent released as a bonus track on the soundtrack of the film Get Rich or Die Tryin' (2005).

The song was originally released in November, 2005 as a bonus track on the Get Rich or Die Tryin' soundtrack.

The remix was set to be featured on Olivia's sophomore album, "Behind Closed Doors", which was ultimately shelved.

The remix made its album debut in parts of Europe on 2006 editions of 50 Cent's The Massacre and Bulletproof soundtrack.

An official music video for the remix was released in 2006 featuring Olivia and cameos from G-Unit members Mobb Deep, Spider Loc and Hot Rod.