Holmes has had a long career, but is best known for his television roles, such as Basqat on Smallville, Marcus Mitchell on True Justice and Frank Pike on Arrow. His most notable role is Nick Barron in the English Language version of 19-2 on Bravo, which garnered him a Canadian Screen Award for Best Actor in a Drama Series in 2017. His film work includes Red Riding Hood, Elysium and The Cabin in the Woods.