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 Warden Boss James Neary on the HBO crime dramaBoardwalk Empire for the first two seasons and Lieutenant Sid Gormley on police dramaBlue Bloods.
Clohessy has had recurring roles in daytime dramas All My Children,Boy Meets World, and Guiding Light. In primetime, he has become known for his multiple regular turns as police officers and other law enforcement officials, creating parallels between his acting career and upbringing by his policeman father. The first of such roles was in the seventh and final season of Hill Street Blues, as Officer Patrick Flaherty. The following season, Clohessy was cast as the new co-star of Pat Morita on the ABC detective series Ohara, playing Lt. George Shaver. He later joined the cast of the HBO prison drama Oz as Correctional OfficerSean Murphy. However, in between these roles, Clohessy had a supporting role as Thomas Smaraldo on NBC's comedy/drama Tattingers, and soon after appeared in a starring role on NBC's short-lived comedy One of the Boys. Clohessy co-starred on the Neal Marlens/Carol Black ABC sitcom Laurie Hill in 1992, playing a stay-at-home freelance writer. In 2008, Clohessy had a regular role in the short-lived Fox show New Amsterdam. He won a Screen Actors Guild Award for Best Ensemble in the HBO series Boardwalk Empire. In feature films, Clohessy played a supporting role in Across the Universe, playing the part of Jude's long-lost father. He played Jack Parker in The Crimson Mask. His largest big budget film role was opposite Ryan Gosling in The Place Beyond the Pines. Onstage, he played Mike in the BroadwayRoundabout Theatre Company revival of Pal Joey, from November, 2008 through February 2009. From 2010 to currently 2020, he has a supporting role as Sid Gormley, on the police drama Blue Bloods. In January of 2012, he played Jack Healy in Season 1/Episode 13 in Unforgettable. In 2012, he portrayed Sergeant Silva, in the film The Avengers.