Robert Clohessy is an American actor. He is best known for playing Correctional Officer Sean Murphy on the HBO prison drama Oz from seasons 3–6, in addition to playing Officer Patrick Flaherty on the NBC police procedural Hill Street Blues, Warden Boss James Neary on the HBO crime drama Boardwalk Empire for the first two seasons and Lieutenant Sid Gormley on the CBS police drama Blue Bloods.
