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).

2019 • TV

2025 • Movie

2013 • TV

2025 • TV

2009 • TV

2019 • Movie
as Colonel John Amen
as Alex Le Domas
as Captain Marks
as Jake
as Rob Meadows
as Carter Mitchum
as Curtis
as Mark
as Paul
as Cyrus Frear
as Larsen Rogers
as Jeremiah
as Mason Harper
as Jason
as Darren
as Will
as Elizeus Carrier
as Ace
as Billy Shore
as Terry Sawchuk
Writer
Director
Executive Producer
Director
Director
Writer
Executive Producer
Director
Producer
Producer
as Self
1 episodes
as Randall Tier
2 episodes
as Edmund Cobb
8 episodes
as Jerry Hoffler
1 episodes
as Father Jay
3 episodes
as Tom Rendon
15 episodes
as Grayson Hicks
1 episodes
as Thomas Milligan
7 episodes
as Jimmy Ryan
14 episodes
as Des Courtney
77 episodes
as Officer Logan
8 episodes
as Max Miner
9 episodes
as Charlie
1 episodes