A showing of the movie in Malmö, Sweden led into a brawl in the cinema between supporters of rival soccer teams Malmö FF and Helsingborg IF. The movie was banned from cinemas after the brawl.
During the encounter between Billy Bright and Millwall Fred at the junior game, Frank Harper ad-libbed most of his lines, including the "Kebab shop" racial slur. The anger shown by Tamer Hassan is genuine and Nick Love kept it in the film.
Tommy Johnson walks into a lounge where his friend Rod is playing Grand Theft Auto: Vice City (2002). This game was made by Rockstar Games, who are also credited as being Executive Producers for the movie. Also, Danny Dyer who plays Tommy Johnson in Football Factory was the voice of Kent Paul in Vice City.
Frank Harper is actually an avid Millwall fan. Millwall are the main rivals in the film.
Dougray Scott and Sean Bean were originally in the film before the original script, director and cast were scrapped.