Stephen Root (born November 17, 1951) is an American actor. He has starred as Jimmy James on the NBC sitcom NewsRadio, as Milton Waddams in the film Office Space (1999), and voiced Bill Dauterive and Buck Strickland on the animated series King of the Hill (1997–2010).

Root has appeared in numerous Coen brothers films including O Brother, Where Art Thou? (2000), The Ladykillers (2004), No Country for Old Men (2007), The Ballad of Buster Scruggs (2018), The Tragedy of Macbeth (2021). Other notable film roles include in Dave (1993), DodgeBall (2004), Idiocracy (2006), Cedar Rapids (2011), Selma (2014), Trumbo (2015), Get Out (2017), and On the Basis of Sex (2018).

His television roles have included Capt. K'Vada in the Star Trek: The Next Generation two-part episode "Unification" (1991), Hawthorne Abendsen in seasons 2–4 of the series The Man in the High Castle. He has supporting roles in a variety of HBO series, including Boardwalk Empire, True Blood, Perry Mason, and Succession. He notably starred as Monroe Fuches / The Raven on the HBO dark comedy series Barry (2018–2023), for which he was nominated for a Primetime Emmy Award for Outstanding Supporting Actor in a Comedy Series in 2019.