Michael O'Neill photo

Michael O'Neill

Acting
1947-05-29
Montgomery, Alabama, USA
​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 101 titles
NCIS (2003) subtitle poster
NCIS
2003 TV
as Riley McCallister
Subtitles
The Mentalist (2008) subtitle poster
The Mentalist
2008 TV
as Sheriff Nelson
Subtitles
Grey's Anatomy (2005) subtitle poster
Grey's Anatomy
2005 TV
as Gary Clark
Subtitles
Criminal Minds (2005) subtitle poster
Criminal Minds
2005 TV
as Det. Yarbough
Subtitles
CSI: Miami (2002) subtitle poster
CSI: Miami
2002 TV
as Jerry Blackburn
Subtitles
24 (2001) subtitle poster
24
2001 TV
as Richard Walsh
Subtitles
24 (2001) subtitle poster
24
2001 TV
as Richard Welsh
Subtitles
S.W.A.T. (2017) subtitle poster
S.W.A.T.
2017 TV
as Carl Luca
Subtitles
Prison Break (2005) subtitle poster
Prison Break
2005 TV
as Herb Stanton
Subtitles
The X-Files (1993) subtitle poster
The X-Files
1993 TV
as Patrol Captain Van Gelder
Subtitles
NCIS: Los Angeles (2009) subtitle poster
NCIS: Los Angeles
2009 TV
as Ret. U.S. Army General Richard Collins
Subtitles
Sons of Anarchy (2008) subtitle poster
Sons of Anarchy
2008 TV
as Anthony Franklin
Subtitles
Tracker (2024) subtitle poster
Tracker
2024 TV
as Buck Avery
Subtitles
War of the Worlds (2025) subtitle poster
War of the Worlds
2025 Movie
as Secretary of Defense Walter Crystal
Subtitles
Fringe (2008) subtitle poster
Fringe
2008 TV
as Sheriff Velchik
Subtitles
ER (1994) subtitle poster
ER
1994 TV
as Col. Ken Kilner
Subtitles
JAG (1995) subtitle poster
JAG
1995 TV
as Commander Bradley
Subtitles
The West Wing (1999) subtitle poster
The West Wing
1999 TV
as Ron Butterfield
Subtitles
The Resident (2018) subtitle poster
The Resident
2018 TV
as Joshua Williams
Subtitles
Without a Trace (2002) subtitle poster
Without a Trace
2002 TV
as Thomas Shannon
Subtitles
This Is Us (2016) subtitle poster
This Is Us
2016 TV
as Arlo
Subtitles
Scandal (2012) subtitle poster
Scandal
2012 TV
as Lonnie Mencken
Subtitles
Ghost Whisperer (2005) subtitle poster
Ghost Whisperer
2005 TV
as Nolan
Subtitles
Boston Legal (2004) subtitle poster
Boston Legal
2004 TV
as Dr. Robert McLean
Subtitles
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