Catherine Spaak (3 April 1945 – 17 April 2022) was a French-Italian actress, singer, model, and media personality. 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.

A member of the prominent Spaak family, Catherine was the daughter of Belgian screenwriter Charles Spaak and French actress Claudie Clèves (née Alice Perrier). Her older sister was actress Agnès Spaak. Her uncle, politician Paul-Henri Spaak, was the Prime Minister of Belgium from 1947 to 1949 and one of the founding fathers of the European Union. Her paternal grandmother was Marie Janson Spaak, Belgium's first female member of Parliament.

Spaak was born on 3 April 1945 just outside of Paris in Boulogne-Billancourt, Hauts-de-Seine. Initially she wanted to be a ballerina and studied ballet in her youth, until she gave it up after being told she was too tall.

Spaak was inspired to be an actress when in the summer of 1955, she accompanied her father to a film set, where she saw Gina Lollobrigida. In response to her parents announcing that they were divorcing and eager to leave the boarding school, Spaak left home at the age of 15 and moved to Italy, where she settled and eventually became a naturalized citizen.

Spaak's first role was in the French 13-minute short L'hiver (1959), directed by Jacques Gautier, which was followed by a brief uncredited role in the French prison break film Le Trou (1960), which was directed by Jacques Becker. Spaak's brief appearance in Le Trou caught the eye of a Paris television reporter, and his subsequent interview with her was seen by Sophia Loren who thought that Spaak would be suitable for a major role in Sweet Deceptions, a film that her producer husband Carlo Ponti was intending to make in Rome. Released in 1960, Spaak's role as a 17-year-old student who has an affair with a middle-aged man brought her to attention of the wider public.

Spaak soon became a teenage star and It girl, and between the ages 15 to 18, she was the lead actress in at least 12 movies. In her initial roles, her dialogues were dubbed until she had learned Italian. 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.

As an adult, Spaak appeared in many comedies and a few dramas from the mid-1960s through the early 1980s. 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), For Love and Gold (1966, written by Age & Scarpelli), Adultery Italian Style (1966). Her first film role in an American production was as the mistress of an investor who wants to buy a landmark New Orleans hotel in the 1967 release Hotel.

Spaak's next significant role was as a young widow opposite Jean-Louis Trintignant in the 1968 sex comedy The Libertine. 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), Honey (1981) and Alice (2010, written and directed by Oreste Crisostomi).