A member of the Spaak family, she was known as an iconic "It girl" in Italy during the 1960s, becoming a star of commedia all'italiana films, before later becoming prominent as a talk show host and media personality.

In response to her parents announcing that they were divorcing and eager to leave the boarding school,[10] Spaak left home at the age of 15 and moved to Italy, where she settled[9] and eventually became a naturalized citizen.

Media coverage at the time dubbed her a "new woman of the '60s", and her hairstyle and fashion sense became oft-imitated by teenage girls throughout Italy.

Among her most notable titles are Circle of Love (1964, directed by Roger Vadim), The Man, the Woman and the Money (1965, starring Marcello Mastroianni),[13] The Incredible Army of Brancaleone (1966, written by Age & Scarpelli), Adultery Italian Style (1966).

This was followed by Diary of a Telephone Operator (1969, with Claudia Cardinale), the giallo film The Cat o' Nine Tails (1971, written and directed by Dario Argento), the nunsploitation film Story of a Cloistered Nun (1973), the controversial comedy My Darling Slave (1973), the Spaghetti Western Take a Hard Ride (1975) opposite Jim Brown and Lee Van Cleef, Sunday Lovers (1980), Miele di donna (1981) and Alice (2010, written and directed by Oreste Crisostomi).

She originated the role of Rossana in the Riccardo Pazzaglia-Domenico Modugno musical Cyrano (unrelated to the Anthony Burgess-Michael J. Lewis production of the same name) in 1979.

Her first marriage was on 30 January 1963 at the age of 18 to actor Fabrizio Capucci, whom she had met on the set of the film La voglia matta (1962) and with whom she had a daughter, Sabrina.