Olivia Haigh Williams (born 26 July 1968) is an English film, stage and television actress who has appeared in British and American films and television series.
Williams was born in Camden Town, London. Both of her parents are barristers. Williams was educated at South Hampstead High School, an independent school for girls in Hampstead in North London, followed by Newnham College at the University of Cambridge, from which she graduated with a degree in English literature. She then studied drama at the Bristol Old Vic Theatre School for two years and spent three years at the Royal Shakespeare Company.
After graduation, Williams worked with the Royal Shakespeare Company in both Stratford-upon-Avon and London. In 1995, she toured the United States in a production of Shakespeare's Richard III starring Ian McKellen. Her first significant appearance before the cameras was as Jane Fairfax in the British TV film Emma (1996), based on Jane Austen's 1816 novel.
Williams made her film debut in 1997's The Postman, after doing a screen test for Kevin Costner. She later won the lead role of Rosemary Cross in Wes Anderson's Rushmore (1998). She then starred as Bruce Willis' wife in the blockbuster The Sixth Sense (1999).