McGrath starred in the TV mini-series The Roaring Twenties and the film Eden. In 2008 she made an appearance in an episode of The Tudors. Katie’s best known roles came as Morgana on the series Merlin from 2008 to 2012, and as Lucy Westernra on the series Dracula from 2013 to 2014. She has starred in the films Freakdog, W.E., and Leading Lady. She also appeared in episodes of The Queen, Labyrinth, and Dates. McGrath is starred as Beth in the 2015 movie Jurassic World. She won 2nd place at the 2013 SFX Awards, UK for Best Actress in Merlin.
