She is best known for her film roles in Tom Jones (1963), which earned her an Academy Award nomination, Hombre (1967) and The Wicker Man (1973).

[9] After graduation, Cilento found work on stage almost immediately and was signed to a five-year contract by Alexander Korda.

In 1956, she was nominated for a Tony Award for Best Supporting or Featured Actress (Dramatic) for Helen of Troy in Jean Giraudoux's Tiger at the Gates.

She was nominated for the Academy Award for Best Supporting Actress for her performance in Tom Jones in 1963[15] and appeared in The Third Secret the following year.

In the 1980s, she settled in Mossman, north of Cairns, where she built her own outdoor theatre, named "Karnak", in the tropical rainforest.