Katherine Elizabeth "Katie" McGrath (born 21 February 1983) is an Irish actress and model from Ashford, County Wicklow, Ireland, best known for playing Morgana Pendragon in the BBC One TV series Merlin. She portrays Lucy Westenra in the tv series, Dracula.
McGrath studied the International Baccalaureate at St. Andrews College before graduating from Trinity College, Dublin with a degree in History. She wanted to work in fashion journalism and took a job at Image magazine, before becoming a wardrobe assistant on the set of The Tudors.
While working on The Tudors, McGrath was advised to try acting, so she sent photographs around Irish agents. She said:DS: "A couple of the producers said I should give acting a try. I just thought. Why not? It’s like running away to join the circus, everyone wants to do it when they’re young but then you grow up and get a proper job. But somebody’s got to do it or you wouldn’t have the circus".
McGrath was cast in Damage, an Irish TV-movie in 2007. She also starred in Bedrock Productions's play La Marea at the Dublin Theatre Festival 2007.
She appeared in the feature films Eden and Freakdog in 2008, before being cast in Merlin.
In 2009, McGrath starred in a five-part docudrama for Channel 4 exploring the life of Queen Elizabeth II, The Queen, in which she played a young Princess Margaret.
In 2010, McGrath was cast in Madonna's directorial debut W.E., a King Edward VIII biopic. McGrath played Lady Furness, the king's former mistress who introduces him to Wallis Simpson.
In February 2011, McGrath began filming the comedy-drama film A Princess for Christmas in Romania. The film premiered in December 2011.
In September 2011, McGrath voice-acted the lead character in the Irish animated short film Tríd an Stoirm (Through the Storm). Later that month, McGrath was cast as Oriane Congost in Labyrinth.
In February 2013, McGrath was reunited with her The Tudors co-worker and close friend Jonathan Rhys Meyers in NBC and Sky Living's horror drama TV series Dracula, which is due to air autumn 2013. McGrath portrayed Lucy Westerna.
In June 2013, McGrath starred in the Channel 4 show Dates alongside Gemma Chan as a young lesbian on the dating scene. In 2015 she co-starred in Jurassic World as Zara.
In 2016, it was announced that McGrath would play the recurring role of Lena Luthor in the second season of Supergirl. She appeared in the season two premier episode entitled "The Adventures of Supergirl" and was promoted to a series regular in March 2017 for the third season.
She appeared as Elsa in Guy Richie's fantasy film King Arthur: Legend of the Sword, which was released in May 2017.
McGrath is set to star in the television film Buttons, which is set to premier on PBS.