Stephen John Dillane (born 27 March 1957) is an English actor. On screen, he is best known for his roles as Leonard Woolf in the movie The Hours (2002), Thomas Jefferson in the HBO miniseries John Adams (2008), Stannis Baratheon in the fantasy series Game of Thrones (2012–15) and DCI Karl Roebuck in The Tunnel (2013–17). His TV work has earned him a BAFTA and International Emmy Award, as well as a Primetime Emmy Award nomination.
As a stage actor, Dillane won a Tony Award for his lead performance in Tom Stoppard's play The Real Thing (2000). He also had praised performances in Angels in America (1993), Hamlet (1994) and Macbeth (2005).
Dillane was born in Kensington, London. His mother was English and his father was an Australian. He is married to Naomi Wirthner. The couple have two children, including actor Frank Dillane.