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

Transformers

as Tom Banacheck

Grey's Anatomy

as Gary Clark

Dallas Buyers Club

as Richard Barkley

Prison Break

as Herb Stanton

The Mentalist

as Sheriff Nelson

Criminal Minds

as Det. Yarbough

The X-Files

as Patrol Captain Van Gelder

Sons of Anarchy

as Anthony Franklin

Fringe

as Sheriff Velchik

J. Edgar

as Senator McKellar