Mark O'Brien

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

The Kelly Clarkson Show

Hannibal

Republic of Doyle

Warehouse 13

Arrival

Perry Mason

Halt and Catch Fire

Killjoys

All Movies (43)

• The Outer Threat2026
• The Voices of Our Mother2026 · as William
• Nuremberg2025 · as Colonel John Amen
• The Memory Keeper2025 · as Elizeus Carrier
• Shadow of God2025 · as Mason Harper
• Seven Veils2025 · as Paul
• Topper2025 · as Topper
• Blue Bayou2021 · as Ace
• The Righteous2021 · as Aaron Smith
• Hammer2019 · as Chris Davis
• Marriage Story2019 · as Carter Mitchum
• Ready or Not2019 · as Alex
• Goalie2019 · as Terry Sawchuk
• State Like Sleep2019 · as Darren
• The Front Runner2018 · as Billy Shore
• Bad Times at the El Royale2018 · as Larsen Rogers
• Kin2018 · as Jake
• The Darkest Minds2018 · as Rob Meadows
• How It Ends2018 · as Jeremiah
• Anon2018 · as Cyrus Frear
• Parallel2018 · as Josh
• Arrival2016 · as Captain Marks
• Wanderer2016 · as Eric
• The Dark Stranger2016 · as Mark
• How to Plan an Orgy in a Small Town2015 · as Bruce Buck
• End of Days, Inc.2015 · as Jason
• Dennis2015 · as Dennis
• Sweetieface2013 · as Sam
• Beat Down2012 · as Michael
• Snarbuckled2010 · as Jacob O'Higgins
• Brad2010 · as Brad
• Grown Up Movie Star2010 · as Will
• Mum's the Word2009 · as Curtis
• Quiet at Dawn2009 · as Watts
• Cut from the Same Cloth2009 · as Jack Cochrane
• Heartless Disappearance Into Labrador Seas2008 · as Charlie
• Epilogue2008 · as Henry
• The One That Got Away2008 · as Tommy Palchek
• The Four Horsemen2008 · as Eric Rollins
• Better People— · as John
• Nice People—
• Good in the Room— · as Charlie
• Little One—

All TV Shows (13)

• The Copenhagen Test2025 · as Edmund Cobb
• The Sticky2024 · as Charlie
• 61st Street2022 · as Officer Logan
• Your Honor2020 · as Father Jay
• Perry Mason2020 · as Thomas Milligan
• The Kelly Clarkson Show2019 · as Self
• City on a Hill2019 · as Jimmy Ryan
• The Last Tycoon2017 · as Max Miner
• Killjoys2015 · as Grayson Hicks
• Halt and Catch Fire2014 · as Tom Rendon
• Hannibal2013 · as Randall Tier
• Republic of Doyle2010 · as Des Courtney
• Warehouse 132009 · as Jerry Hoffler