Actor · DirectorMark O'BrienMay 7, 1984(39 years old)St. John's, CanadaMark 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.SocialsTwitterIMDbKnown forArrivalCaptain MarksMarriage StoryCarter MitchumHannibalRandall TierThe Front RunnerBilly ShoreBad Times at the El RoyaleLarsen RogersAnonCyrus FrearPerry MasonThomas MilliganYour HonorFather JayThe Darkest MindsRob MeadowsHalt and Catch FireTom RendonWarehouse 13Jerry HofflerHow It EndsJeremiah