Ian McDiarmid is a Scottish actor and theatre director who has also made sporadic appearances on television, and appeared in 47 films since 1976. Internationally, he is perhaps most famous for his role as Emperor Palpatine/Darth Sidious in the Star Wars saga, which he reprised in The Rise of Skywalker, the final installment in the Star Wars sequel trilogy. He also played Brother Jacobus in Dragonslayer and Ambrose in Restoration. Archive recording of him can be heard in the Star Wars: Clone Wars episode "Shattered".
McDiarmid also portrayed Professor Levi in The Young Indiana Jones Chronicles episode "Paris, October 1916" (later edited into The Adventures of Young Indiana Jones: (Chapter 9) "Demons of Deception").