Fagin is a fictional character in the Charles Dickens novel Oliver Twist. He is the leader of a group of children, the Artful Dodger among them, whom he teaches to make their livings by pickpocketing and other criminal activities. Bill Sykes, the major villain of the novel, is one of Fagin's old pupils.

Arguably the definitive portrayal of Fagin, among the many stage and screen adaptations of the novel, is Alec Guinness' performance in the 1948 film version directed by David Lean. Ron Moody's portrayal in the musical Oliver, another memorable version, is recognisably influenced by Guinness' portrayal.