Denis Patrick Seamus O'Hare (born January 17, 1962) is an American actor noted for his award-winning performances in the plays Take Me Out and Sweet Charity, as well as portraying the vampire Russell Edgington on HBO's fantasy series True Blood. He is also known for his supporting roles in such films as Charlie Wilson's War, Milk, Changeling and Dallas Buyers Club. In 2011, he starred as Larry Harvey in the first season of the FX anthology series American Horror Story, for which he was nominated for a Primetime Emmy Award for Outstanding Supporting Actor in a Miniseries or a Movie in 2012. He returned to the show in 2013, playing Spalding in American Horror Story: Coven and once more as Stanley in American Horror Story: Freak Show, the latter for which he earned a second Primetime Emmy Award nomination. For his performance in American Horror Story: Hotel as Liz Taylor, O'Hare received universal critical acclaim.
O'Hare was born in Kansas City, Missouri, the son of Margaret Karene (née Kennedy; January 25, 1931–October 8, 2008) and John M. O'Hare. He has three sisters, Pam, Patricia and Kathleen, and one brother, Michael. O'Hare grew up in the suburbs of Detroit, living in Southfield until he was 15, when his family moved to Wing Lake in Bloomfield Hills. His mother was a musician and he grew up playing the church organ. O'Hare is of Irish descent and holds an Irish passport.
As a teenager, O'Hare was in his school's choir and in 1974 he went to his first audition, gaining a chorus part in a community theatre production of Show Boat. In 1980, O'Hare left Detroit for Chicago to study theatre at Northwestern University.
O'Hare has been married to Hugo Redwood since July 28, 2011, and the couple have an adopted son, Declan.