TMDBFrom the public credits

Michael O'Neill

Actor · Producer

Tells you when a new project gets a date

1947Born, Montgomery

80Credits

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…

Known for

TransformersTom Banacheck

Grey's AnatomyGary Clark

Dallas Buyers ClubRichard Barkley

Prison BreakHerb Stanton

The MentalistSheriff Nelson

Filmography

All Acting Producing

2025War of the WorldsSecretary of Defense Walter CrystalMovie

2025Bride HardFrankMovie

2025Happy FaceD.A. Craig Calloway · 5 episodesShow

2024Happy's PlaceJim Jackoway · 2 episodesShow

2024TrackerBuck Avery · 1 episodeShow

2023AirJoe DeanMovie

2022Fire CountryHarlan Denbo · 1 episodeShow

2022EchoesVictor McCleary · 7 episodesShow

2022Outer RangeJudge Pettigrew · 2 episodesShow

2021Cold CallChristianMovie

2020The Stand at Paxton CountyDell ConnellyMovie

2020MessiahCameron Collier · 5 episodesShow

2019ClemencyChaplain David KendricksMovie

2018IndivisibleChaplain RogersMovie

2018The RomanoffsRon Hopkins · 1 episodeShow

2018Danger OneBeckwithMovie

2018Tom Clancy's Jack RyanSenator Mitchell Chapin · 5 episodesShow

2018The ResidentJoshua Williams · 1 episodeShow

2017S.W.A.T.Carl Luca · 3 episodesShow

2017On Yoga: The Architecture of PeaceProducerMovie

2016ShooterRay Brooks · 3 episodesShow

2016This Is UsArlo · 1 episodeShow

201611.22.63Arliss Price · 1 episodeShow

2014ManhattanPsychiatrist · 1 episodeShow

2014ExtantAlan Sparks · 13 episodesShow

2014The Grim SleeperDetective SimmsMovie

2013Dallas Buyers ClubRichard BarkleyMovie

2013RectifySenator Roland Foulkes · 15 episodesShow

2013Bates MotelNick Ford · 8 episodesShow

2012VegasMayor Ted Bennett · 4 episodesShow

2012ScandalLonnie Mencken · 5 episodesShow

2011J. EdgarSenator McKellarMovie

2010Law & Order: LAJeb Monroe · 1 episodeShow

2010Rizzoli & IslesJonathan McKnight · 1 episodeShow

2010The GladesTrent Staley · 1 episodeShow

2010Green ZoneColonel BethelMovie

2010Flying LessonsChief DobbsMovie

2009FlashForwardCIA Director Keller · 1 episodeShow

2009NCIS: Los AngelesRet. U.S. Army General Richard Collins · 1 episodeShow

2008Nothing but the TruthCIA DirectorMovie

2008LeverageJudge Roy · 1 episodeShow

2008A Quiet Little MarriageBruceMovie

2008The MentalistSheriff Nelson · 1 episodeShow

2008FringeSheriff Velchik · 1 episodeShow

2008Sons of AnarchyAnthony Franklin · 1 episodeShow

2008CrazyRalph ChristiansonMovie

2007TransformersTom BanacheckMovie

2007Army WivesReverend Bankerd · 2 episodesShow

2006The NinePete Burton · 3 episodesShow

2006The UnitRon Cheals · 6 episodesShow

2005Commander in ChiefCongressman Wilcox · 2 episodesShow

2005Ghost WhispererNolan · 1 episodeShow

2005Criminal MindsDet. Yarbough · 1 episodeShow

2005Close to HomeDon Wheeler · 1 episodeShow

2005Prison BreakHerb Stanton · 1 episodeShow

2005Grey's AnatomyGary Clark · 3 episodesShow

2005Numb3rsBoyd Keene · 1 episodeShow

2004Around the BendCowboyMovie

2004Boston LegalDr. Robert McLean · 1 episodeShow

2004LAXAlonso Mathews · 1 episodeShow

2004American CrimeSheriff SmythMovie

2003NCISRiley McCallister · 3 episodesShow

2003Secondhand LionsRalphMovie

2003SeabiscuitMr. PollardMovie

2003DreamcatcherGen. MathesonMovie

2002The Emperor's ClubCo-ProducerMovie

2002Without a TraceThomas Shannon · 1 episodeShow

2002CSI: MiamiJerry Blackburn · 1 episodeShow

200124Richard Welsh, Richard Walsh · 1 episodeShow

2001Crossing JordanChris Benz · 1 episodeShow

2000TrafficLawyer RodmanMovie

2000The Legend of Bagger VanceO.B. KeelerMovie

2000Boston PublicDr. Bernard Colbert · 4 episodesShow

1999RoswellPhilip Evans · 1 episodeShow

1999The West WingRon Butterfield · 15 episodesShow

1999ATFATF Asst. Director Ben WalkerMovie

1999The Mod SquadGreeneMovie

1998Dancer, Texas Pop. 81Mr. LuskMovie

1998Virtual ObsessionMovie

1998StandoffCult Leader (Voice)Movie

Is this you?

Link these credits to your frames profile.

Link your credits