Tatiana Maslany Sarah, Beth Actor Jordan Gavaris Felix Actor Kevin Hanchard Art Actor Ari Millen Mark, Ira Actor Kristian Bruun Donnie Actor Josh Vokey Scott Actor Maria Doyle Kennedy Mrs. S Actor Skyler Wexler Kira Guest Star Rosemary Dunsmore Susan Duncan Guest Star Stephen McHattie P.T. Westmoreland Guest Star Tom Cullen Leonard Sipp Guest Star Kyra Harper Dr. Virginia Coady Guest Star Jenessa Grant Mud Guest Star Andrew Moodie Mr. Frontenac Guest Star Cara Ricketts Brie Guest Star Ivan Schneeberg Executive Producer David Fortier Executive Producer