Zoë Wanamaker (born 13 May 1949) is an American-born British actress who has worked extensively with the Royal Shakespeare Company and the National Theatre. Wanamaker was appointed a Commander of the Order of the British Empire in 2001 by Queen Elizabeth II. She has received numerous accolades including a Laurence Olivier Award and nominations for three BAFTA Awards, and four Tony Awards.

A nine-time Olivier Award nominee, she won for Once in a Lifetime (1979) and Electra (1998). She has also received four Tony Award nominations for her work on Broadway; for Piaf (1981), Loot (1986), Electra (1999), and Awake and Sing! (2006).

She has acted in the films Wilde (1997), Harry Potter and the Philosopher's Stone (2001), and My Week with Marilyn (2011). She was twice nominated for the BAFTA TV Award for Best Actress, for Prime Suspect (1991) and Love Hurts (1992–1994). She portrayed Susan Harper in the sitcom My Family (2000–2011), and appeared in the ITV dramas Agatha Christie's Poirot (2005–2013), Mr Selfridge (2015), and Girlfriends (2018).

Zoë Wanamaker was born in New York City on 13 May 1949, the daughter of Canadian actress and radio performer Charlotte Holland and American actor, film director, and radio producer Sam Wanamaker (born Samuel Wattenmacker). Her father was of Ukrainian-Jewish descent, although she had a secular and non-observant upbringing. The BBC series Who Do You Think You Are?, broadcast on 24 February 2009, revealed that her paternal grandfather Maurice Wanamaker (originally Manus Watmacher) was a tailor from Mykolaiv.

Whilst working in the United Kingdom in 1952, Wanamaker's father found out he had been blacklisted in Hollywood. Her parents therefore decided to remain in the UK. She was educated at the independent King Alfred School in Hampstead and at Sidcot School, a Quaker boarding school in Winscombe, Somerset. Zoe attended Hornsey College of Art for the Pre-Diploma Course before going on to study acting at the Central School of Speech and Drama.

Wanamaker's career started in the theatre. From 1976 to 1984 she was a member of the Royal Shakespeare Company. She won an Olivier Award for her 1979 performance in Once in a Lifetime and a second for Sophocles' Electra in 1998. In 1985, she played Verdi's wife Giuseppina Strepponi in the original production of After Aida. She appeared on stage playing the part of Beatrice opposite Simon Russell Beale as Benedick in the National Theatre's production of Much Ado About Nothing. She has received Tony Award nominations for her performances in Piaf, Loot, Electra, and Awake and Sing!.

In 1997, Wanamaker was the first person to speak on the stage of the newly completed replica theatre, Shakespeare's Globe, on London's South Bank. This was in recognition of the role played by her father in founding the new theatre. She subsequently became Honorary President of the Globe.

From May to October 2010, Wanamaker appeared in Arthur Miller's All My Sons as Kate Keller at the Apollo Theatre on Shaftesbury Avenue in London.