The show is loosely based on the Hollywood experiences of Mark Wahlberg, one of the executive producers.
Kevin Connolly had actually retired from acting when show creators first approached about doing the show. It wasn't until he was informed the part of Eric had been written specifically for him that he decided to take part.
The character of Billy Walsh is mainly based on show writer Rob Weiss and director Vincent Gallo. The story of Medellin getting trashed at the Cannes Film Festival was loosely based on Gallo's highly-criticized movie The Brown Bunny (2003).
Johnny Drama is based on actor Johnny Alves, Mark Wahlberg's cousin. Thus, in the pilot, Turtle mentioning that Vince thought Johnny was his cousin until they were fourteen.