Acting
Michael O'Neill
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.
Filmography
War of the Worlds
Film · 2025
Bride Hard
Film · 2025
Happy Face
Series · 2025
Happy's Place
Series · 2024
Tracker
Series · 2024
Air
Film · 2023
Echoes
Series · 2022
Fire Country
Series · 2022
Outer Range
Series · 2022
Cold Call
Film · 2021
The Stand at Paxton County
Film · 2020
Messiah
Series · 2020
Clemency
Film · 2019
Indivisible
Film · 2018
Danger One
Film · 2018
The Resident
Series · 2018
Tom Clancy's Jack Ryan
Series · 2018
The Romanoffs
Series · 2018
S.W.A.T.
Series · 2017
This Is Us
Series · 2016
11.22.63
Series · 2016
Shooter
Series · 2016
The Grim Sleeper
Film · 2014
Extant
Series · 2014
Manhattan
Series · 2014
Dallas Buyers Club
Film · 2013
Bates Motel
Series · 2013
Rectify
Series · 2013
Scandal
Series · 2012
Vegas
Series · 2012
J. Edgar
Film · 2011
Green Zone
Film · 2010
Flying Lessons
Film · 2010
The Glades
Series · 2010
Rizzoli & Isles
Series · 2010
Law & Order: LA
Series · 2010
FlashForward
Series · 2009
NCIS: Los Angeles
Series · 2009
A Quiet Little Marriage
Film · 2008
Nothing But the Truth
Film · 2008
Crazy
Film · 2008
Sons of Anarchy
Series · 2008
The Mentalist
Series · 2008
Fringe
Series · 2008
Leverage
Series · 2008
Transformers
Film · 2007
Army Wives
Series · 2007
The Nine
Series · 2006
The Unit
Series · 2006
Ghost Whisperer
Series · 2005
Grey's Anatomy
Series · 2005
Prison Break
Series · 2005
Commander in Chief
Series · 2005
Criminal Minds
Series · 2005
Numb3rs
Series · 2005
Close to Home
Series · 2005
Around the Bend
Film · 2004
American Crime
Film · 2004
LAX
Series · 2004
Boston Legal
Series · 2004
Dreamcatcher
Film · 2003
Secondhand Lions
Film · 2003
Seabiscuit
Film · 2003
NCIS
Series · 2003
Without a Trace
Series · 2002
CSI: Miami
Series · 2002
24
Series · 2001
24
Series · 2001
Crossing Jordan
Series · 2001
The Legend of Bagger Vance
Film · 2000
Traffic
Film · 2000
Boston Public
Series · 2000
ATF
Film · 1999
The Mod Squad
Film · 1999
Roswell
Series · 1999
The West Wing
Series · 1999
Dancer, Texas Pop. 81
Film · 1998
Virtual Obsession
Film · 1998
Standoff
Film · 1998
The Shining
Series · 1997
Ally McBeal
Series · 1997
The Practice
Series · 1997
The Sunchaser
Film · 1996
Millennium
Series · 1996
Bushwhacked
Film · 1995
Awake to Danger
Film · 1995
JAG
Series · 1995
Blind Justice
Film · 1994
Beyond Betrayal
Film · 1994
Chicago Hope
Series · 1994
One West Waikiki
Series · 1994
ER
Series · 1994
For Their Own Good
Film · 1993
Victim of Love: The Shannon Mohr Story
Film · 1993
The X-Files
Series · 1993
Diagnosis: Murder
Series · 1993
The Gun in Betty Lou's Handbag
Film · 1992
Jennifer Eight
Film · 1992
Lorenzo's Oil
Film · 1992
An Unremarkable Life
Film · 1989
Sea of Love
Film · 1989
Ghost Story
Film · 1981