Aidan Murphy (born 24 April 1968), better known as Aidan Gillen (/ˈɡɪlən/), is an Irish actor. He is known for his roles as Stuart Alan Jones in Queer as Folk (1999–2000); Tommy Carcetti in The Wire (2004–2008); John Boy in  Love/Hate (2010–2011); Petyr "Littlefinger" Baelish in Game of Thrones (2011–2017), Aberama Gold in Peaky Blinders (2017–2019); as Milo Sunter on Mayor of Kingstown (2021–present); and as Frank Kinsella, in the crime drama Kin (2021–2023). His film roles include CIA operative Bill Wilson in The Dark Knight Rises (2012), Janson in Maze Runner: The Scorch Trials (2015), and John Reid in Bohemian Rhapsody (2018), and several films directed by Jamie Thraves.

He has received three Irish Film & Television Awards and has been nominated for a British Academy Television Award, a British Independent Film Award, and a Tony Award.