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.
War of the Worlds
2025
Bride Hard
Frank
2025
Happy's Place
Jim Jackoway · (2 episodes)
2024
Air
Joe Dean
2023
Fire Country
Harlan Denbo · (1 episode)
2022
Echoes
Victor McCleary · (7 episodes)
2022
Outer Range
Judge Pettigrew · (2 episodes)
2022
Cold Call
Christian
2021
The Stand at Paxton County
Dell Connelly
2020
Messiah
Cameron Collier · (5 episodes)
2020
Clemency
Chaplain David Kendricks
2019
Indivisible
Chaplain Rogers
2018
The Romanoffs
Ron Hopkins · (1 episode)
2018
Danger One
Beckwith
2018
Tom Clancy's Jack Ryan
Senator Mitchell Chapin · (5 episodes)
2018
The Resident
Joshua Williams · (1 episode)
2018
S.W.A.T.
Carl Luca · (3 episodes)
2017
Shooter
Ray Brooks · (3 episodes)
2016
This Is Us
Arlo · (1 episode)
2016
11.22.63
Arliss Price · (1 episode)
2016
Manhattan
Psychiatrist · (1 episode)
2014
Extant
Alan Sparks · (13 episodes)
2014
The Grim Sleeper
Detective Simms
2014
Dallas Buyers Club
Richard Barkley
2013
Rectify
Senator Roland Foulkes · (15 episodes)
2013
Bates Motel
Nick Ford · (8 episodes)
2013
Scandal
Lonnie Mencken · (5 episodes)
2012
J. Edgar
Senator McKellar
2011
Law & Order: LA
Jeb Monroe · (1 episode)
2010
Rizzoli & Isles
Jonathan McKnight · (1 episode)
2010
The Glades
Trent Staley · (1 episode)
2010
Green Zone
Colonel Bethel
2010
FlashForward
CIA Director Keller · (1 episode)
2009
NCIS: Los Angeles
Ret. U.S. Army General Richard Collins · (1 episode)
2009
Nothing But the Truth
CIA Director
2008
Leverage
Judge Roy · (1 episode)
2008
A Quiet Little Marriage
Bruce
2008
The Mentalist
Sheriff Nelson · (1 episode)
2008
Fringe
Sheriff Velchik · (1 episode)
2008
Sons of Anarchy
Anthony Franklin · (1 episode)
2008
Crazy
Ralph Christianson
2008
Transformers
Tom Banacheck
2007
The Nine
Pete Burton · (3 episodes)
2006
The Unit
Ron Cheals · (1 episode)
2006
Commander in Chief
Congressman Wilcox · (2 episodes)
2005
Ghost Whisperer
Nolan · (1 episode)
2005
Criminal Minds
Det. Yarbough · (1 episode)
2005
Prison Break
Herb Stanton · (1 episode)
2005
Grey's Anatomy
Gary Clark · (4 episodes)
2005
Around the Bend
Cowboy
2004
LAX
Alonso Mathews · (1 episode)
2004
American Crime
Sheriff Smyth
2004
NCIS
Riley McCallister · (3 episodes)
2003
Secondhand Lions
Ralph
2003
Seabiscuit
Mr. Pollard
2003
Dreamcatcher
General Matheson
2003
Without a Trace
Thomas Shannon · (1 episode)
2002
24
Richard Welsh · (1 episode)
2001
24
Richard Walsh · (1 episode)
2001
Crossing Jordan
Chris Benz · (1 episode)
2001
Traffic
Lawyer Rodman
2000
The Legend of Bagger Vance
O.B. Keeler
2000
Boston Public
Dr. Bernard Colbert · (4 episodes)
2000
Roswell
Philip Evans · (1 episode)
1999
The West Wing
Ron Butterfield · (15 episodes)
1999
ATF
ATF Asst. Director Ben Walker
1999
The Mod Squad
Greene
1999
Dancer, Texas Pop. 81
Mr. Lusk
1998
Virtual Obsession
1998
Standoff
Cult Leader (Voice)
1998
Ally McBeal
Dr. Colbert · (1 episode)
1997
The Shining
Daniel Edwards (uncredited) · (1 episode)
1997
The Practice
Judge Robert Temple · (1 episode)
1997
Millennium
County Prosecutor Calvin Smith · (1 episode)
1996
The Sunchaser
Agent Moreland
1996
JAG
Commander Bradley · (1 episode)
1995
Bushwhacked
Jon Jordan
1995
Awake to Danger
Detective Brickman
1995
Beyond Betrayal
Ray Pasquerello
1994
ER
Col. Ken Kilner · (1 episode)
1994
Chicago Hope
(1 episode)
1994
One West Waikiki
(1 episode)
1994
Blind Justice
Spencer Heymen
1994
Victim of Love: The Shannon Mohr Story
Dick Britton
1993
Diagnosis: Murder
Sheriff Buck O'Hara · (1 episode)
1993
The X-Files
Patrol Captain Van Gelder · (1 episode)
1993
For Their Own Good
Clark Thompson
1993
Lorenzo's Oil
School Psychologist
1992
Jennifer Eight
Serato
1992
The Gun in Betty Lou's Handbag
Jergens
1992
An Unremarkable Life
Michael
1989
Sea of Love
Raymond Brown
1989
Ghost Story
Churchill
1981