About:
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
• 
  Seven Veils
  as
  Paul
• 
  The Four Horsemen
  as
  Eric Rollins
• 
  Grown Up Movie Star
  as
  Will
• 
  Cut from the Same Cloth
  as
  Jack Cochrane
• 
  Heartless Disappearance Into Labrador Seas
  as
  Charlie