Michael O'Neill

Personal Info

Known For

Acting

Known Credits

98

Gender

Male

Birthday

1947-05-29 (78 years old)

Place of Birth

Montgomery, Alabama, USA

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

  • War of the Worlds

    War of the Worlds

  • Grey's Anatomy

    Grey's Anatomy

  • NCIS

    NCIS

  • Criminal Minds

    Criminal Minds

  • The Mentalist

    The Mentalist

  • Prison Break

    Prison Break

  • S.W.A.T.

    S.W.A.T.

  • 24

    24

  • 24

    24

  • NCIS: Los Angeles

    NCIS: Los Angeles

  • Sons of Anarchy

    Sons of Anarchy

  • The X-Files

    The X-Files

  • JAG

    JAG

  • The Resident

    The Resident

  • Fringe

    Fringe

  • The West Wing

    The West Wing

  • Diagnosis: Murder

    Diagnosis: Murder

  • Without a Trace

    Without a Trace

  • Ghost Whisperer

    Ghost Whisperer

  • Boston Legal

    Boston Legal

  • This Is Us

    This Is Us

  • Scandal

    Scandal

  • ER

    ER

  • The Practice

    The Practice

  • Crossing Jordan

    Crossing Jordan

  • Numb3rs

    Numb3rs

  • Rizzoli & Isles

    Rizzoli & Isles

  • Fire Country

    Fire Country

  • Chicago Hope

    Chicago Hope

  • Tom Clancy's Jack Ryan

    Tom Clancy's Jack Ryan

  • Bates Motel

    Bates Motel

  • Bride Hard

    Bride Hard

  • Leverage

    Leverage

  • Boston Public

    Boston Public

  • The Unit

    The Unit

  • Shooter

    Shooter

  • Outer Range

    Outer Range

  • Army Wives

    Army Wives

  • Roswell

    Roswell

  • Millennium

    Millennium

  • The Glades

    The Glades

  • Law & Order: LA

    Law & Order: LA

  • Close to Home

    Close to Home

  • Ally McBeal

    Ally McBeal

  • FlashForward

    FlashForward

  • Air

    Air

  • Extant

    Extant

  • Commander in Chief

    Commander in Chief

  • Rectify

    Rectify

  • Secondhand Lions

    Secondhand Lions

  • Messiah

    Messiah

  • 11.22.63

    11.22.63

  • Manhattan

    Manhattan

  • Traffic

    Traffic

  • Happy Face

    Happy Face

  • Dreamcatcher

    Dreamcatcher

  • The Shining

    The Shining

  • Seabiscuit

    Seabiscuit

  • Green Zone

    Green Zone

  • An Unremarkable Life

    An Unremarkable Life

  • The Grim Sleeper

    The Grim Sleeper

  • Dallas Buyers Club

    Dallas Buyers Club

  • The Romanoffs

    The Romanoffs

  • Nothing But the Truth

    Nothing But the Truth

  • LAX

    LAX

  • Virtual Obsession

    Virtual Obsession

  • One West Waikiki

    One West Waikiki

  • Transformers

    Transformers

  • Awake to Danger

    Awake to Danger

  • A Quiet Little Marriage

    A Quiet Little Marriage

  • The Stand at Paxton County

    The Stand at Paxton County

  • Happy's Place

    Happy's Place

  • Dancer, Texas Pop. 81

    Dancer, Texas Pop. 81

  • J. Edgar

    J. Edgar

  • The Nine

    The Nine

  • Sea of Love

    Sea of Love

  • Jennifer Eight

    Jennifer Eight

  • Echoes

    Echoes

  • Lorenzo's Oil

    Lorenzo's Oil

  • Standoff

    Standoff

  • The Legend of Bagger Vance

    The Legend of Bagger Vance

  • The Sunchaser

    The Sunchaser

  • Blind Justice

    Blind Justice

  • Indivisible

    Indivisible

  • Bushwhacked

    Bushwhacked

  • Clemency

    Clemency

  • Crazy

    Crazy

  • Around the Bend

    Around the Bend

  • The Gun in Betty Lou's Handbag

    The Gun in Betty Lou's Handbag

  • For Their Own Good

    For Their Own Good

  • ATF

    ATF

  • Beyond Betrayal

    Beyond Betrayal

  • Danger One

    Danger One

  • The Mod Squad

    The Mod Squad

  • American Crime

    American Crime

  • Ghost Story

    Ghost Story

  • Cold Call

    Cold Call

  • Victim of Love: The Shannon Mohr Story

    Victim of Love: The Shannon Mohr Story