
Michael O'Neill
Known for department: Acting
Birthday: 1947-05-29
Place of birth: Montgomery, Alabama, USA
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

Transformers
2007Tom Banacheck
Green Zone
2010Colonel Bethel
Dreamcatcher
2003Gen. Matheson
The Gun in Betty Lou's Handbag
1992Jergens
Air
2023Joe Dean
Around the Bend
2004Cowboy
Blind Justice
1994Spencer Heymen
A Quiet Little Marriage
2008Bruce
Dancer, Texas Pop. 81
1998Mr. Lusk
War of the Worlds
2025Secretary of Defense Walter Crystal
Dallas Buyers Club
2013Richard Barkley
For Their Own Good
1993Clark Thompson
An Unremarkable Life
1989Michael
Bride Hard
2025Frank
Bushwhacked
1995Jon Jordan
The Grim Sleeper
2014Detective Simms
Virtual Obsession
1998
The Legend of Bagger Vance
2000O.B. Keeler
Traffic
2000Lawyer Rodman