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).
The Kelly Clarkson Show
Series • 2019
Warehouse 13
Series • 2009
Hannibal
Series • 2013
Halt and Catch Fire
Series • 2014
Republic of Doyle
Series • 2010
Arrival
Movie • 2016
Killjoys
Series • 2015
Perry Mason
Series • 2020
Your Honor
Ready or Not
Movie • 2019
61st Street
Series • 2022
City on a Hill
Nuremberg
Movie • 2025
The Copenhagen Test
Series • 2025
Marriage Story
Bad Times at the El Royale
Movie • 2018
The Darkest Minds
The Last Tycoon
Series • 2017
The Sticky
Series • 2024
Kin
Anon
How It Ends
The Front Runner
Parallel
Beat Down
Movie • 2012
Blue Bayou
Movie • 2021
Shadow of God
The Outer Threat
Movie • 2026
How to Plan an Orgy in a Small Town
Movie • 2015
Seven Veils