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
Nuremberg
Col. John Amen
2025
Shadow of God
Mason Harper
2025
Seven Veils
Paul
2025
Topper
Topper
2025
The Sticky
Charlie · (1 episode)
2024
61st Street
Officer Logan · (8 episodes)
2022
Blue Bayou
Ace
2021
The Righteous
Aaron Smith
2021
Your Honor
Father Jay · (3 episodes)
2020
Perry Mason
Thomas Milligan · (7 episodes)
2020
Hammer
Chris Davis
2019
Marriage Story
Carter Mitchum
2019
The Kelly Clarkson Show
(1 episode)
2019
Ready or Not
Alex Le Domas
2019
City on a Hill
Jimmy Ryan · (14 episodes)
2019
Goalie
Terry Sawchuk
2019
State Like Sleep
Darren
2019
The Front Runner
Billy Shore
2018
Bad Times at the El Royale
Larsen Rogers
2018
Kin
Jake
2018
The Darkest Minds
Rob Meadows
2018
How It Ends
Jeremiah
2018
Anon
Cyrus Frear
2018
Parallel
Josh
2018
The Last Tycoon
Max Miner · (9 episodes)
2017
Arrival
Captain Marks
2016
Wanderer
Eric
2016
The Dark Stranger
Mark
2016
How to Plan an Orgy in a Small Town
Bruce Buck
2015
Killjoys
Grayson Hicks · (1 episode)
2015
End of Days, Inc.
Jason
2015
Dennis
Dennis
2015
Halt and Catch Fire
Tom Rendon · (15 episodes)
2014
Hannibal
Randall Tier · (2 episodes)
2013
Sweetieface
Sam
2013
Beat Down
Michael
2012
Snarbuckled
Jacob O'Higgins
2010
Brad
Brad
2010
Republic of Doyle
Des Courtney · (77 episodes)
2010
Mum's the Word
Curtis
2009
Grown Up Movie Star
Will
2009
Warehouse 13
Jerry Hoffler · (1 episode)
2009
Cut from the Same Cloth
Jack Cochrane
2009
Heartless Disappearance Into Labrador Seas
Charlie
2008
The Four Horsemen
Eric Rollins
2008
The Voices of Our Mother
William
Epilogue
Henry
2008
The Embers and the Stars
Falsehood
Elizeus Carrier
Quiet at Dawn
Watts
2009
The One That Got Away
Tommy Palchek
2008
Better People
John
The Copenhagen Test
Cobb · (2 episodes)