Mark O'Brien
Acting

Mark O'Brien

Born 1984-05-07 · St. John's, Canada

Mark O'Brien (born May 7, 1984) is a Canadian actor and director. He is best known for playing the role of Des Courtney in Republic of Doyle and Tom Rendon in Halt and Catch Fire.

ActorWriterDirectorCastExecutive Producer

Known for

Arrival★ 7.6Viewing moment
Arrival
2016
Ready or Not★ 7.1Viewing moment
Ready or Not
2019
The Darkest Minds★ 7Viewing moment
The Darkest Minds
2018
Bad Times at the El Royale★ 6.8Viewing moment
Bad Times at the El Royale
2018
Anon★ 5.9Viewing moment
Anon
2018
Marriage Story★ 7.8Viewing moment
Marriage Story
2019
How to Plan an Orgy in a Small Town★ 5.1Viewing moment
How to Plan an Orgy in a Small Town
2015
How It Ends★ 5.3Viewing moment
How It Ends
2018
Kin★ 6.2Viewing moment
Kin
2018
Parallel★ 6Viewing moment
Parallel
2018
Halt and Catch Fire★ 7.9Viewing moment
Halt and Catch Fire
2014 · Series
Republic of Doyle★ 7Viewing moment
Republic of Doyle
2010 · Series
Blue Bayou★ 7.5Viewing moment
Blue Bayou
2021
The Front Runner★ 5.9Viewing moment
The Front Runner
2018
The Outer Threat★ 5.8Viewing moment
The Outer Threat
2026
City on a Hill★ 7.3Viewing moment
City on a Hill
2019 · Series
The Four Horsemen★ 4.5Viewing moment
The Four Horsemen
2008
State Like Sleep★ 5Viewing moment
State Like Sleep
2019
End of Days, Inc.★ 5.6Viewing moment
End of Days, Inc.
2015
The Copenhagen Test★ 6.5Viewing moment
The Copenhagen Test
2025 · Series
61st Street★ 6.6Viewing moment
61st Street
2022 · Series
Hammer★ 5.4Viewing moment
Hammer
2019
The Last Tycoon★ 7Viewing moment
The Last Tycoon
2017 · Series
The Righteous★ 6.2Viewing moment
The Righteous
2021
The Dark Stranger★ 5.4Viewing moment
The Dark Stranger
2016
Grown Up Movie Star★ 5.4Viewing moment
Grown Up Movie Star
2009
Goalie★ 7Viewing moment
Goalie
2019
Beat DownViewing moment
Beat Down
2012
SnarbuckledViewing moment
Snarbuckled
2010
The Voices of Our Mother★ 6.4Viewing moment
The Voices of Our Mother
2026
Topper★ 5.3Viewing moment
Topper
2025

Frequent collaborators

Mayko NguyenMayko NguyenHenry CzernyHenry CzernyAlex Ozerov-MeyerAlex Ozerov-MeyerLanette WareLanette WareAmanda ClaytonAmanda ClaytonKristian BruunKristian BruunAnna FergusonAnna FergusonJonny HarrisJonny Harris