The daughter of Argentine tango singer Osvaldo Ribó, Hussey was born in Buenos Aires but 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 reunited with Zeffirelli in the miniseries Jesus of Nazareth (1977) as Mary and appeared as Rosalie Otterbourne in John Guillermin's Agatha Christie adaptation Death on the Nile (1978).

In 1990 she appeared in two horror productions, Stephen King's It and Psycho IV: The Beginning, in which she portrayed Norman Bates' mother.

[3] There, Hussey was accepted into the Italia Conti Academy drama school, which she attended for five years, taking modeling and walk-on parts to help pay her fees.

In 1964, she appeared in an episode of the television series Drama, followed by minor roles in two films the following year: The Battle of the Villa Fiorita and Cup Fever.

[8][3][9] Hussey appeared in a West End production of The Prime of Miss Jean Brodie, playing Jenny opposite Vanessa Redgrave.

[10] Italian film director Franco Zeffirelli noticed her performance because "she was the only choice mature enough with experience and natural beauty to play Juliet while still looking 14.

[12][13] Derek Smith of Slant said Hussey's performance "captures the passion and yearning of love-struck teens in a very contemporary manner".

[17] A memoir, The Girl on the Balcony: Olivia Hussey Finds Life After Romeo and Juliet, was published on 31 July 2018.

"[19][20] In another 2018 interview with Variety, Hussey defended the nude scene, saying, "Nobody my age had done that before," adding that Zeffirelli shot it tastefully.

[23][24] The complainants stated that director Franco Zeffirelli, who died in 2019, initially said they would wear flesh-coloured undergarments and be positioned in a way that would not show nudity, but that Whiting's bare buttocks and Hussey's bare breasts are nonetheless briefly shown during the scene, in violation of California state and federal laws against indecency and the exploitation of children.

[27] In her 2018 memoir, Hussey recalled that she had "mumbled something about being interested in Anne of the Thousand Days" but that she "couldn't see herself with Wayne", concluding that this "adolescent and opinionated" remark ended her professional relationship with Wallis, who immediately withdrew his offer.

[34] In 1987, Hussey, along with several well-known actors, made a cameo appearance in a clip for the Michael Jackson video "Liberian Girl".

[45] Hussey was slated to reprise her role as Jess Bradford in the Black Christmas fan film It's Me, Billy: Chapter 2, but withdrew from the project in November 2023 due to health reasons.

[55] After being in remission for nearly a decade, the breast cancer returned in 2017, with Hussey undergoing chemotherapy and radiation treatment to remove a small tumour growing between her heart and lungs.