
Actor
Mark O'Brien
Born 1984 · St. Johns, Newfoundland, Canada
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).
Directed
Acting

Arrival
Captain Marks · 2016

Marriage Story
Carter Mitchum · 2019

Hannibal
Randall Tier · 2013

Ready or Not
Alex · 2019

Your Honor
Father Jay · 2020

Bad Times at the El Royale
Larsen Rogers · 2018

The Darkest Minds
Rob Meadows · 2018

Nuremberg
Colonel John Amen · 2025

Warehouse 13
Jerry Hoffler · 2009

Halt and Catch Fire
Tom Rendon · 2014

Anon
Cyrus Frear · 2018

Killjoys
Grayson Hicks · 2015

Perry Mason
Thomas Milligan · 2020

Blue Bayou
Ace · 2021

Kin
Jake · 2018

How It Ends
Jeremiah · 2018

City on a Hill
Jimmy Ryan · 2019

The Front Runner
Billy Shore · 2018

The Sticky
Charlie · 2024

Parallel
Josh · 2018

The Last Tycoon
Max Miner · 2017

The Copenhagen Test
Edmund Cobb · 2025

The Kelly Clarkson Show
Self · 2019

Republic of Doyle
Des Courtney · 2010



