Mark O'Brien
![Mark O'Brien](http://image.tmdb.org/t/p/h632/8ckgltvlife4BBJcBpHEQWXfQ9p.jpg)
Known For: Acting
Gender: Male
Date of Birth: May 7, 1984 (40 years old)
Place of Birth: St. Johns, Newfoundland, Canada
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).