Michael O'Neill is an American actor who usually portrays senior law enforcement or military officers and is best known for his role as Special Agent Ron Butterfield, the head of President Josiah Bartlet's Secret Service detail, on the political drama television series The West Wing, from 1999-2006.
He also has a starring role as Alan Sparks, the director of ISEA (International Space Exploration Agency), in the science fiction mystery thriller television series Extant, executive produced by Steven Spielberg.
O'Neill portrayed Richard Barkley in the acclaimed film Dallas Buyers Club. His additional film credits include J. Edgar, Transformers, Sea of Love and Seabiscuit.
O'Neill played Nick Ford in the series Bates Motel. Other television appearances include Senator Roland Foulkes in the series Rectify and New York Hawks' interim General Manager Hank Griffin in Necessary Roughness.
His additional credits include NCIS, Vegas, Numb3rs, The Unit, Grey's Anatomy, Sons of Anarchy and as fan-favourite Special Agent Ron Butterfield in the critically acclaimed series The West Wing.
Born in Montgomery, Alabama, O'Neill is a graduate of Auburn University and began his acting career under the mentorship of Will Geer at the Theatricum Botanicum in Los Angeles. He divides his time between Los Angeles and Birmingham, Alabama.