Image of Michael O'Neill

Michael O'Neill

​From Wikipedia, the free encyclopedia. Michael O'Neill is an American actor. With a career stretching through three decades, he usually portrays senior law enforcement or military officers. He is perhaps best known for his role as Special agent Ron Butterfield, the head of President Josiah Bartlet's Secret Service detail, on The West Wing. He played CTU Administrative Director Richard Walsh in the first two episodes of 24. He played Sgt. Maj. Ron Cheals in the CBS action-drama series The Unit. He starred in the Season Six 2 part Finale of Grey's Anatomy as the broken widower who holds the hospital hostage with a 9mm while pursuing the doctors responsible for unplugging his wife. His most notable film performances occur in Seabiscuit, Secondhand Lions, Transformers, Dancer, Texas Pop 81, Traffic, Sea of Love, A Quiet Little Marriage, Nothing But the Truth, and Green Zone. O'Neill graduated from Auburn University in 1974. After attending Auburn he spent time under the tutelage of actor Will Geer and his daughter, Ellen, at Theatricum Botanicum in Los Angeles before moving to New York to pursue his career there.


Read bio at tmdb | Read bio at Wikipedia
Movie/TV Credits:
62
First Appeared:
In the movie War of the Worlds
Latest Project:
Movie Air 2023-04-05
Known For
Poster of Indivisible
Poster of A Quiet Little Marriage
Poster of Grey's Anatomy
Poster of Virtual Obsession
Filmography
Movie War of the Worlds 2025
Movie Air Joe Dean 2023-04-05
Series Echoes Victor McCleary 2022-08-19
Movie Cold Call Christian 2021-02-04
Movie The Stand at Paxton County Dell Connelly 2020-05-02
Movie Clemency Chaplain David Kendricks 2019-12-27
Series The Resident Joshua Williams 2018-01-21
Movie Danger One Beckwith 2018-09-14
Movie Indivisible Chaplain Rogers 2018-10-26
Series 11.22.63 Mr. Price 2016-02-15
Movie The Grim Sleeper Detective Simms 2014-03-15
Series Extant Alan Sparks 2014-07-09
Series Bates Motel Nick Ford 2013-03-18
Series Rectify Senator Roland Foulkes 2013-04-22
Movie Dallas Buyers Club Richard Barkley 2013-11-01
Series Scandal Lonnie Mencken 2012-04-05
Movie J. Edgar Senator McKellar 2011-11-09
Series Rizzoli & Isles Jonathan McKnight 2010-07-12
Series The Glades Trent Staley 2010-07-11
Movie Green Zone Colonel Bethel 2010-03-11
Series FlashForward CIA Director Keller 2009-09-24
Series Fringe Unknown 2008-09-09
Movie Crazy Ralph Christianson 2008-03-02
Series The Mentalist Sheriff Nelson 2008-09-23
Movie Nothing But the Truth CIA Director 2008-12-19
Movie A Quiet Little Marriage Bruce 2008-10-18
Movie Transformers Tom Banacheck 2007-06-27
Series The Nine Pete Burton 2006-10-04
Series Prison Break Unknown 2005-08-29
Series Grey's Anatomy Unknown 2005-03-27
Movie American Crime Sheriff Smyth 2004-04-06
Movie Around the Bend Cowboy 2004-10-08
Movie Dreamcatcher General Matheson 2003-03-21
Movie Seabiscuit Mr. Pollard 2003-07-22
Movie Secondhand Lions Ralph 2003-09-19
Series 24 Richard Walsh 2001-11-06
Movie The Legend of Bagger Vance O.B. Keeler 2000-11-02
Movie Traffic Lawyer Rodman 2000-12-27
Movie The Mod Squad Greene 1999-03-26
Series Roswell Unknown 1999-10-06
Series The West Wing Unknown 1999-09-22
Movie ATF Asst. A.T.F. Director Ben Walker 1999-09-06
Movie Virtual Obsession 1998-02-01
Movie Dancer, Texas Pop. 81 Mr. Lusk 1998-05-01
Movie The Sunchaser Agent Moreland 1996-05-29
Movie Awake to Danger Detective Brickman 1995-03-12
Series Blue Murder Bruce Lyons 1995-09-14
Movie Bushwhacked Jon Jordan 1995-08-04
Movie Blind Justice Spencer Heymen 1994-06-25
Series Chicago Hope Unknown 1994-09-18
Movie For Their Own Good Clark Thompson 1993-04-05
Movie Victim of Love: The Shannon Mohr Story Dick Britton 1993-11-09
Series The X-Files Unknown 1993-09-10
Movie The Gun in Betty Lou's Handbag Jergens 1992-08-21
Movie Jennifer Eight Serato 1992-11-06
Movie Lorenzo's Oil School Psychologist 1992-12-30
Movie An Unremarkable Life Michael 1989-10-12
Movie Sea of Love Raymond Brown 1989-09-15
Series Bodyline Viv Richardson 1984-03-19
Movie Molly Lyle 1983-12-27
Movie Ghost Story Churchill 1981-12-18
Movie Joyride Henderson's Assistant 1977-08-17