Mark O'Brien
Biography
Mark O'Brien (born May 7th, 1984) is a Canadian actor and director. He is best known for playing the role of Des Courtney in Republic of Doyle (2010) and Tom Rendon in Halt and Catch Fire (2014).
Known For
TV
The Kelly Clarkson Show
Self
2019
TV
Warehouse 13
Jerry Hoffler
2009
Film
Nuremberg
Colonel John Amen
2025
TV
Hannibal
Randall Tier
2013
TV
Republic of Doyle
Des Courtney
2010
TV
Killjoys
Grayson Hicks
2015
TV
Perry Mason
Thomas Milligan
2020
TV
Halt and Catch Fire
Tom Rendon
2014
Film
Arrival
Captain Marks
2016
TV
Your Honor
Father Jay
2020
Film
Ready or Not
Alex Le Domas
2019
TV
The Copenhagen Test
Edmund Cobb
2025
TV
City on a Hill
Jimmy Ryan
2019
TV
61st Street
Officer Logan
2022
TV
The Sticky
Charlie
2024
Film
Marriage Story
Carter Mitchum
2019
TV
The Last Tycoon
Max Miner
2017
Film
Bad Times at the El Royale
Larsen Rogers
2018
Film
The Darkest Minds
Rob Meadows
2018
Film
Anon
Cyrus Frear
2018
Filmography
2025TVThe Copenhagen Testas Edmund Cobb2025FilmNurembergas Colonel John Amen2025FilmFalsehoodas Elizeus Carrier2025FilmShadow of Godas Mason Harper2025FilmSeven Veilsas Paul2025FilmTopperas Topper2024TVThe Stickyas Charlie2022TV61st Streetas Officer Logan2021FilmBlue Bayouas Ace2021FilmThe Righteousas Aaron Smith2020TVYour Honoras Father Jay2020TVPerry Masonas Thomas Milligan2019FilmHammeras Chris Davis2019FilmMarriage Storyas Carter Mitchum2019TVThe Kelly Clarkson Showas Self2019FilmReady or Notas Alex Le Domas2019TVCity on a Hillas Jimmy Ryan2019FilmGoalieas Terry Sawchuk2019FilmState Like Sleepas Darren2018FilmThe Front Runneras Billy Shore2018FilmBad Times at the El Royaleas Larsen Rogers2018FilmKinas Jake2018FilmThe Darkest Mindsas Rob Meadows2018FilmHow It Endsas Jeremiah2018FilmAnonas Cyrus Frear2018FilmParallelas Josh2017TVThe Last Tycoonas Max Miner2016FilmArrivalas Captain Marks2016FilmWandereras Eric2016FilmThe Dark Strangeras Mark2015FilmHow to Plan an Orgy in a Small Townas Bruce Buck2015TVKilljoysas Grayson Hicks2015FilmEnd of Days, Inc.as Jason2015FilmDennisas Dennis2014TVHalt and Catch Fireas Tom Rendon2013TVHannibalas Randall Tier2013FilmSweetiefaceas Sam2012FilmBeat Downas Michael2010FilmSnarbuckledas Jacob O'Higgins2010FilmBradas Brad2010TVRepublic of Doyleas Des Courtney2009FilmMum's the Wordas Curtis2009FilmGrown Up Movie Staras Will2009FilmQuiet at Dawnas Watts2009TVWarehouse 13as Jerry Hoffler2009FilmCut from the Same Clothas Jack Cochrane2008FilmHeartless Disappearance Into Labrador Seasas Charlie2008FilmEpilogueas Henry2008FilmThe One That Got Awayas Tommy Palchek2008FilmThe Four Horsemenas Eric Rollins—FilmThe Voices of Our Motheras William—FilmThe Outer Threat—FilmBetter Peopleas John—FilmNice People