Zoë Wanamaker, Honorary CBE, is an American-born British actress who lives and works in the United Kingdom. She played the Lady Cassandra O'Brien in the Doctor Who stories The End of the World and New Earth.
Holding both American and British citizenship, she is the daughter of the late American film actor/director/producer Sam Wanamaker, who left the United States for Great Britain after being blacklisted during the 1950s; he led the project to rebuild the Globe Theatre in London.
She is probably best-known by a world-wide audience for her role as Madam Hooch in the film Harry Potter and the Philosopher's Stone (released in the United States as Harry Potter and the Sorcerer's Stone). She played Clarice, one of the dimwitted twin sisters of Lord Groan in Gormenghast, a BBC television adaptation of Mervyn Peake's trilogy. She has also appeared in a variety of films, programmes, and plays.
Coincidentally, a copy of Harry Potter and the Philosopher's Stone can be seen in a Platform One display case during The End of the World.
In the 2009 My Family Christmas Special, a future version of Wanamaker's character makes several references to "moisturising", winking towards the viewer as she does. This is apparently an allusion to her Doctor Who character.