Which actor played the role of Jim Moriarty in the BBC series Sherlock?

Andrew Scott (born 21 October 1976) is an Irish actor. He achieved widespread recognition for playing the role of Jim Moriarty in the BBC series Sherlock, a role that earned him the BAFTA Television Award for Best Supporting Actor.

Andrew Scott made his first appearance as Jim Moriarty in "The Great Game". Steven Moffat (a Scottish television writer and producer) said, "We knew what we wanted to do with Moriarty from the very beginning. Moriarty is usually a rather dull, rather posh villain so we thought someone who was genuinely properly frightening. Someone who's an absolute psycho." Moffat and Gatiss (an English actor, comedian, screenwriter) were originally not going to put a confrontation between Moriarty and Holmes into these three episodes, but after seeing Scott's audition they realised that they "just had to do a confrontation scene. We had to do a version of the scene in 'The Final Problem' in which the two archenemies meet each other."