Katie McGrath () is an Irish actress. In television, she gained recognition for portraying Morgana Pendragon in the BBC One series Merlin (2008–2012), Lucy Westenra on the British-American series Dracula (2013–2014), and Sarah Bennett in the first season of the horror anthology series Slasher (2016), and for her role as Lena Luthor on the superhero series Supergirl (2016–2021). Her film roles include Lady Thelma Furness in the drama film W.E. and Jules Daly in the Christmas movie A Princess for Christmas (2011), Zara Young in the science fiction adventure film Jurassic World (2015), and Elsa in the epic fantasy film King Arthur: Legend of the Sword (2017).