Olivia Hussey (born Olivia Osuna; 17 April 1951) is an English film, stage, and television actress. Her awards include a Golden Globe Award and a David di Donatello Award. The daughter of Argentine opera singer Andrés Osuna, Hussey was born in Buenos Aires and spent most of her early life in her mother's native England. She aspired to become an actress at a young age and studied drama for five years at Italia Conti Academy of Theatre Arts in London.

Hussey began acting professionally as an adolescent. She appeared in a 1966 London production of The Prime of Miss Jean Brodie, opposite Vanessa Redgrave; this led to her being scouted for the role of Juliet in Franco Zeffirelli's 1968 film adaptation of Romeo and Juliet. Hussey received widespread acclaim and international recognition for her performance.

In 1974, she appeared as the lead character Jess Bradford in the cult slasher film Black Christmas. This and subsequent horror films earned her the label of scream queen. She reunited with Zeffirelli in the miniseries Jesus of Nazareth (1977) as Mary and appeared in John Guillermin's Agatha Christie adaptation Death on the Nile (1978). She appeared in several international productions throughout the 1980s, including the Japanese production Virus (1980) and the Australian dystopian action film Turkey Shoot (1982). She appeared in two made-for-television horror productions: Psycho IV: The Beginning and Stephen King's It, both first screened in 1990.

In addition to screen acting, Hussey has worked as a voice actress, providing voice roles in Star Wars video games including Star Wars: Rogue Squadron, Star Wars: Force Commander, and Star Wars: The Old Republic.