Michael O'Neill

Personal Info

Known For

Acting

Known Credits

100

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

  • Grey's Anatomy

    Grey's Anatomy

  • NCIS

    NCIS

  • Criminal Minds

    Criminal Minds

  • War of the Worlds

    War of the Worlds

  • The X-Files

    The X-Files

  • The Mentalist

    The Mentalist

  • 24

    24

  • 24

    24

  • Prison Break

    Prison Break

  • CSI: Miami

    CSI: Miami

  • S.W.A.T.

    S.W.A.T.

  • Sons of Anarchy

    Sons of Anarchy

  • ER

    ER

  • JAG

    JAG

  • The West Wing

    The West Wing

  • Fringe

    Fringe

  • The Resident

    The Resident

  • NCIS: Los Angeles

    NCIS: Los Angeles

  • Tom Clancy's Jack Ryan

    Tom Clancy's Jack Ryan

  • Rizzoli & Isles

    Rizzoli & Isles

  • This Is Us

    This Is Us

  • Ghost Whisperer

    Ghost Whisperer

  • Scandal

    Scandal

  • Numb3rs

    Numb3rs

  • Diagnosis: Murder

    Diagnosis: Murder

  • The Practice

    The Practice

  • Boston Legal

    Boston Legal

  • Without a Trace

    Without a Trace

  • Chicago Hope

    Chicago Hope

  • Crossing Jordan

    Crossing Jordan

  • Leverage

    Leverage

  • Shooter

    Shooter

  • Boston Public

    Boston Public

  • Bates Motel

    Bates Motel

  • Fire Country

    Fire Country

  • Army Wives

    Army Wives

  • Millennium

    Millennium

  • 11.22.63

    11.22.63

  • Bride Hard

    Bride Hard

  • The Unit

    The Unit

  • Ally McBeal

    Ally McBeal

  • Outer Range

    Outer Range

  • Roswell

    Roswell

  • The Glades

    The Glades

  • Extant

    Extant

  • American Crime

    American Crime

  • FlashForward

    FlashForward

  • Close to Home

    Close to Home

  • Dallas Buyers Club

    Dallas Buyers Club

  • Manhattan

    Manhattan

  • Seabiscuit

    Seabiscuit

  • Bushwhacked

    Bushwhacked

  • Law & Order: LA

    Law & Order: LA

  • Danger One

    Danger One

  • Clemency

    Clemency

  • The Mod Squad

    The Mod Squad

  • Green Zone

    Green Zone

  • Rectify

    Rectify

  • Happy Face

    Happy Face

  • Happy's Place

    Happy's Place

  • Commander in Chief

    Commander in Chief

  • Air

    Air

  • Traffic

    Traffic

  • Standoff

    Standoff

  • The Shining

    The Shining

  • Indivisible

    Indivisible

  • ATF

    ATF

  • The Romanoffs

    The Romanoffs

  • LAX

    LAX

  • J. Edgar

    J. Edgar

  • Dreamcatcher

    Dreamcatcher

  • Messiah

    Messiah

  • Transformers

    Transformers

  • An Unremarkable Life

    An Unremarkable Life

  • One West Waikiki

    One West Waikiki

  • Around the Bend

    Around the Bend

  • The Nine

    The Nine

  • Echoes

    Echoes

  • Virtual Obsession

    Virtual Obsession

  • Secondhand Lions

    Secondhand Lions

  • Lorenzo's Oil

    Lorenzo's Oil

  • Sea of Love

    Sea of Love

  • The Legend of Bagger Vance

    The Legend of Bagger Vance

  • Cold Call

    Cold Call

  • Nothing But the Truth

    Nothing But the Truth

  • Jennifer Eight

    Jennifer Eight

  • Ghost Story

    Ghost Story

  • For Their Own Good

    For Their Own Good

  • The Sunchaser

    The Sunchaser

  • Blind Justice

    Blind Justice

  • Crazy

    Crazy

  • The Gun in Betty Lou's Handbag

    The Gun in Betty Lou's Handbag

  • Flying Lessons

    Flying Lessons

  • The Stand at Paxton County

    The Stand at Paxton County

  • The Grim Sleeper

    The Grim Sleeper

  • A Quiet Little Marriage

    A Quiet Little Marriage

  • Dancer, Texas Pop. 81

    Dancer, Texas Pop. 81

  • Victim of Love: The Shannon Mohr Story

    Victim of Love: The Shannon Mohr Story

  • Awake to Danger

    Awake to Danger

  • Beyond Betrayal

    Beyond Betrayal