Margaret Constance "Maisie" Williams (born 15 April 1997) is an English actress. She made her professional acting debut as Arya Stark of Winterfell in the HBO fantasy television series Game of Thrones in 2011, for which she won the EWwy Award for Best Supporting Actress in a Drama, the Portal Award for Best Supporting Actress – Television and Best Young Actor, and the Saturn Award for Best Performance by a Younger Actor. In 2016, she was nominated for a Primetime Emmy Award for Outstanding Supporting Actress in a Drama Series.

Williams has also had a recurring role in Doctor Who as Ashildr in 2015. In addition to television, she made her feature film debut in the mystery The Falling (2014), for which she won the London Film Critics' Circle Award for Young Performer of the Year.