Michael O'Neill
Biography
From Wikipedia, the free encyclopedia. Michael O'Neill (born May 29, 1951) 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.
Known For
All Movies (42)
- War of the Worlds2025 · as Secretary of Defense Walter Crystal
- Bride Hard2025 · as Frank
- Air2023 · as Joe Dean
- Cold Call2021 · as Christian
- The Stand at Paxton County2020 · as Dell Connelly
- Clemency2019 · as Chaplain David Kendricks
- Indivisible2018 · as Chaplain Rogers
- Danger One2018 · as Beckwith
- The Grim Sleeper2014 · as Detective Simms
- Dallas Buyers Club2013 · as Richard Barkley
- J. Edgar2011 · as Senator McKellar
- Green Zone2010 · as Colonel Bethel
- Flying Lessons2010 · as Chief Dobbs
- Nothing But the Truth2008 · as CIA Director
- A Quiet Little Marriage2008 · as Bruce
- Crazy2008 · as Ralph Christianson
- Transformers2007 · as Tom Banacheck
- Around the Bend2004 · as Cowboy
- American Crime2004 · as Sheriff Smyth
- Secondhand Lions2003 · as Ralph
- Seabiscuit2003 · as Mr. Pollard
- Dreamcatcher2003 · as Gen. Matheson
- Traffic2000 · as Lawyer Rodman
- The Legend of Bagger Vance2000 · as O.B. Keeler
- ATF1999 · as ATF Asst. Director Ben Walker
- The Mod Squad1999 · as Greene
- Dancer, Texas Pop. 811998 · as Mr. Lusk
- Virtual Obsession1998
- Standoff1998 · as Cult Leader (Voice)
- The Sunchaser1996 · as Agent Moreland
- Bushwhacked1995 · as Jon Jordan
- Awake to Danger1995 · as Detective Brickman
- Beyond Betrayal1994 · as Ray Pasquerello
- Blind Justice1994 · as Spencer Heymen
- Victim of Love: The Shannon Mohr Story1993 · as Dick Britton
- For Their Own Good1993 · as Clark Thompson
- Lorenzo's Oil1992 · as School Psychologist
- Jennifer Eight1992 · as Serato
- The Gun in Betty Lou's Handbag1992 · as Jergens
- An Unremarkable Life1989 · as Michael
- Sea of Love1989 · as Raymond Brown
- Ghost Story1981 · as Churchill
All TV Shows (60)
- Happy Face2025 · as D.A. Craig Calloway
- Happy's Place2024 · as Jim Jackoway
- Tracker2024 · as Buck Avery
- Fire Country2022 · as Harlan Denbo
- Echoes2022 · as Victor McCleary
- Outer Range2022 · as Judge Pettigrew
- Messiah2020 · as Cameron Collier
- The Romanoffs2018 · as Ron Hopkins
- Tom Clancy's Jack Ryan2018 · as Senator Mitchell Chapin
- The Resident2018 · as Joshua Williams
- S.W.A.T.2017 · as Carl Luca
- Shooter2016 · as Ray Brooks
- This Is Us2016 · as Arlo
- 11.22.632016 · as Arliss Price
- Manhattan2014 · as Psychiatrist
- Extant2014 · as Alan Sparks
- Rectify2013 · as Senator Roland Foulkes
- Bates Motel2013 · as Nick Ford
- Vegas2012 · as Mayor Ted Bennett
- Scandal2012 · as Lonnie Mencken
- Law & Order: LA2010 · as Jeb Monroe
- Rizzoli & Isles2010 · as Jonathan McKnight
- The Glades2010 · as Trent Staley
- FlashForward2009 · as CIA Director Keller
- NCIS: Los Angeles2009 · as Ret. U.S. Army General Richard Collins
- Leverage2008 · as Judge Roy
- The Mentalist2008 · as Sheriff Nelson
- Fringe2008 · as Sheriff Velchik
- Sons of Anarchy2008 · as Anthony Franklin
- Army Wives2007 · as Reverend Bankerd
- The Nine2006 · as Pete Burton
- The Unit2006 · as Ron Cheals
- Commander in Chief2005 · as Congressman Wilcox
- Ghost Whisperer2005 · as Nolan
- Criminal Minds2005 · as Det. Yarbough
- Close to Home2005 · as Don Wheeler
- Prison Break2005 · as Herb Stanton
- Grey's Anatomy2005 · as Gary Clark
- Numb3rs2005 · as Boyd Keene
- Boston Legal2004 · as Dr. Robert McLean
- LAX2004 · as Alonso Mathews
- NCIS2003 · as Riley McCallister
- Without a Trace2002 · as Thomas Shannon
- CSI: Miami2002 · as Jerry Blackburn
- 242001 · as Richard Walsh
- 242001 · as Richard Welsh
- Crossing Jordan2001 · as Chris Benz
- Boston Public2000 · as Dr. Bernard Colbert
- Roswell1999 · as Philip Evans
- The West Wing1999 · as Ron Butterfield
- Ally McBeal1997 · as Dr. Colbert
- The Shining1997 · as Daniel Edwards (uncredited)
- The Practice1997 · as Judge Robert Temple
- Millennium1996 · as County Prosecutor Calvin Smith
- JAG1995 · as Commander Bradley
- ER1994 · as Col. Ken Kilner
- Chicago Hope1994 · as Bill Wyzinski
- One West Waikiki1994
- Diagnosis: Murder1993 · as Sheriff Buck O'Hara
- The X-Files1993 · as Patrol Captain Van Gelder






