|Date of Birth||7 May 1984|
|Place of Birth||St. John's, Newfoundland, Canada|
|Height||6' 2½" (1.89 m)|
|Mark O'Brien gallery|
Mark O'Brien was born on May 7, 1984 in St. John's, Newfoundland, Canada. He is an actor and director, known for Republic of Doyle (2010), Grown Up Movie Star (2009) and The End of Days at Godfrey Global Inventory (2015). He has been married to Georgina Reilly since January 6, 2013.
He is married to Georgina Reilly.
He portrays Randall Tier in NBC Hannibal's season two.