Aidan Murphy (born 24 April 1968), better known as Aidan Gillen, is an Irish actor. He is the recipient of three Irish Film & Television Awards and has been nominated for a British Academy Television Award, a British Independent Film Award, and a Tony Award.

On television, he played Stuart Alan Jones in the Channel 4 series Queer as Folk (1999–2000), Tommy Carcetti in the HBO series The Wire (2004–2008), John Boy in the RTÉ series Love/Hate (2010–2011), Petyr "Littlefinger" Baelish in the HBO series Game of Thrones (2011–2017), and Dr. J. Allen Hynek in The History Channel's Project Blue Book (2019–2020). Gillen also featured as Aberama Gold in the BBC TV drama series “Peaky Blinders” 2017-2019. In 2021, he appeared in the crime dramas Mayor of Kingstown and Kin.

His film roles include Miles Jackson in 12 Rounds (2009), CIA operative Bill Wilson in The Dark Knight Rises (2012), Janson in Maze Runner: The Scorch Trials (2015) and Maze Runner: The Death Cure (2018), Robert in The Lovers (2017), Queen's manager John Reid in Bohemian Rhapsody (2018), and Jack Blackwell in Those Who Wish Me Dead (2021). He also provided the voice and motion capture for Paul Serene in the 2016 video game Quantum Break.