[1] In 2001, Roberts made his television debut in the war drama miniseries Band of Brothers in the episode "Crossroads".

In 2005, Roberts made his film debut in the thriller movie by Nicolas Forzy titled Ambition.

On the same year, he took on a supporting role in the action comedy police procedural series Taxi Brooklyn and appeared on the first season of the BBC Two Wolf Hall, which is based on the book of the same name about 1500s England.

In 2016, Roberts joined the cast of Starz's Black Sails as Governor Woodes Rogers, a formidable foe to the pirates of Nassau.

[6] He also appeared as the legendary knight Ser Arthur Dayne in sixth season of HBO's Game of Thrones.