Actor profile

Mark O'Brien

7th May 1984 St. Johns, Newfoundland, Canada Acting

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).

40 Movies 13 TV Shows 1 In Production 54 Credits

Filmography

Movies & TV Shows

Nuremberg poster

Nuremberg 6th November 2025 as Colonel John Amen

The Memory Keeper poster

The Memory Keeper 26th October 2025 as Elizeus Carrier

Shadow of God poster

Shadow of God 26th March 2025 as Mason Harper

Seven Veils poster

Seven Veils 7th March 2025 as Paul

Topper poster

Topper 4th March 2025 as Topper

Blue Bayou poster

Blue Bayou 10th September 2021 as Ace

The Righteous poster

The Righteous 15th August 2021 as Aaron Smith

Hammer poster

Hammer 5th December 2019 as Chris Davis

Marriage Story poster

Marriage Story 28th September 2019 as Carter Mitchum

Ready or Not poster

Ready or Not 21st August 2019 as Alex

Goalie poster

Goalie 1st March 2019 as Terry Sawchuk

State Like Sleep poster

State Like Sleep 4th January 2019 as Darren

The Front Runner poster

The Front Runner 6th November 2018 as Billy Shore

Bad Times at the El Royale poster

Bad Times at the El Royale 4th October 2018 as Larsen Rogers

Kin poster

Kin 29th August 2018 as Jake

The Darkest Minds poster

The Darkest Minds 25th July 2018 as Rob Meadows

How It Ends poster

How It Ends 13th July 2018 as Jeremiah

Anon poster

Anon 3rd May 2018 as Cyrus Frear

Parallel poster

Parallel 10th April 2018 as Josh

Arrival poster

Arrival 10th November 2016 as Captain Marks

Wanderer poster

Wanderer 4th October 2016 as Eric

The Dark Stranger poster

The Dark Stranger 15th July 2016 as Mark

How to Plan an Orgy in a Small Town poster

How to Plan an Orgy in a Small Town 19th September 2015 as Bruce Buck

End of Days, Inc. poster

End of Days, Inc. 24th April 2015 as Jason

Dennis poster

Dennis 18th April 2015 as Dennis

Sweetieface 1st January 2013 as Sam

Beat Down poster

Beat Down 3rd August 2012 as Michael

Snarbuckled poster

Snarbuckled 18th September 2010 as Jacob O'Higgins

Brad 24th July 2010 as Brad

Grown Up Movie Star poster

Grown Up Movie Star 29th January 2010 as Will

Mum's the Word 23rd October 2009 as Curtis

Quiet at Dawn 1st September 2009 as Watts

Cut from the Same Cloth 1st January 2009 as Jack Cochrane

Heartless Disappearance Into Labrador Seas poster

Heartless Disappearance Into Labrador Seas 9th September 2008 as Charlie

Epilogue 27th June 2008 as Henry

The One That Got Away poster

The One That Got Away 20th April 2008 as Tommy Palchek

The Four Horsemen poster

The Four Horsemen 18th March 2008 as Eric Rollins

Better People as John

Nice People

The Outer Threat

The Copenhagen Test poster

The Copenhagen Test 27th December 2025 as Edmund Cobb

The Sticky poster

The Sticky 6th December 2024 as Charlie

61st Street poster

61st Street 10th April 2022 as Officer Logan

Your Honor poster

Your Honor 6th December 2020 as Father Jay

Perry Mason poster

Perry Mason 21st June 2020 as Thomas Milligan

The Kelly Clarkson Show poster

The Kelly Clarkson Show 9th September 2019 as Self

City on a Hill poster

City on a Hill 16th June 2019 as Jimmy Ryan

The Last Tycoon poster

The Last Tycoon 28th July 2017 as Max Miner

Killjoys poster

Killjoys 19th June 2015 as Grayson Hicks

Halt and Catch Fire poster

Halt and Catch Fire 1st June 2014 as Tom Rendon

Hannibal poster

Hannibal 4th April 2013 as Randall Tier

Republic of Doyle poster

Republic of Doyle 6th January 2010 as Des Courtney

Warehouse 13 poster

Warehouse 13 7th July 2009 as Jerry Hoffler

The Voices of Our Mother poster

Coming soon

The Voices of Our Mother 19th June 2026 as William