Mark O'Brien
Acting
52
Acting Credits
6
Directed
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
Filmography
The Voices of Our Mother
2026
as William
The Outer Threat
2026
as Daniel Ashford
Seven Veils
2025
as Paul
Shadow of God
2025
as Mason Harper
Nuremberg
2025
as Colonel John Amen
The Memory Keeper
2025
as Elizeus Carrier
Topper
2025
as Topper
The Copenhagen Test
2025
as Edmund Cobb
The Sticky
2024
as Charlie
61st Street
2022
as Officer Logan
Blue Bayou
2021
as Ace
The Righteous
2021
as Aaron Smith
Perry Mason
2020
as Thomas Milligan
Your Honor
2020
as Father Jay
State Like Sleep
2019
as Darren
Marriage Story
2019
as Carter Mitchum
Goalie
2019
as Terry Sawchuk
Hammer
2019
as Chris Davis
Ready or Not
2019
as Alex
The Kelly Clarkson Show
2019
as Self
City on a Hill
2019
as Jimmy Ryan
Anon
2018
as Cyrus Frear
Kin
2018
as Jake
Parallel
2018
as Josh
The Darkest Minds
2018
as Rob Meadows
Bad Times at the El Royale
2018
as Larsen Rogers
The Front Runner
2018
as Billy Shore
How It Ends
2018
as Jeremiah
The Last Tycoon
2017
as Max Miner
The Dark Stranger
2016
as Mark
Arrival
2016
as Captain Marks
Wanderer
2016
as Eric
End of Days, Inc.
2015
as Jason
How to Plan an Orgy in a Small Town
2015
as Bruce Buck
Dennis
2015
as Dennis
Killjoys
2015
as Grayson Hicks
Halt and Catch Fire
2014
as Tom Rendon
Sweetieface
2013
as Sam
Hannibal
2013
as Randall Tier
Beat Down
2012
as Michael
Grown Up Movie Star
2010
as Will
Snarbuckled
2010
as Jacob O'Higgins
Brad
2010
as Brad
Republic of Doyle
2010
as Des Courtney
Cut from the Same Cloth
2009
as Jack Cochrane
Mum's the Word
2009
as Curtis
Quiet at Dawn
2009
as Watts
Warehouse 13
2009
as Jerry Hoffler
The Four Horsemen
2008
as Eric Rollins
Heartless Disappearance Into Labrador Seas
2008
as Charlie
Epilogue
2008
as Henry
The One That Got Away
2008
as Tommy Palchek