The future Capucine was born Germaine Hélène Irène Lefebvre on 6 January 1928 in Saint-Raphaël, Var, France. She often confused the issue of her birth by claiming that she was born in 1931 or 1933, and most sources indicate those years. She attended school in Saumur, France, and received a B.A. in foreign languages.
In 1945, at age 17, while riding in a carriage in Paris, Lefebvre was noticed by a commercial photographer. Adopting the name "Capucine" (French for nasturtium), she became a fashion model, working for fashion houses Givenchy and Christian Dior.
Capucine met Audrey Hepburn while modeling for Givenchy in Paris. The two would remain close friends for the rest of Capucine's life.
In 1949, Capucine made her film debut in the French film Rendez-vous de juillet.
In 1957, film producer Charles K. Feldman spotted Capucine while she was modeling in New York City. Feldman brought her to Hollywood to learn English and study acting under Gregory Ratoff. She was signed to a contract with Columbia Pictures in 1958 and landed her first English-speaking role in the film Song Without End (1960) for which she was nominated for a Golden Globe Award.
Over the next few years, Capucine made six more major motion pictures, including North to Alaska (1960), a comedy, as a prostitute who becomes the love interest of John Wayne, and Walk on the Wild Side (1962), in which she portrayed a redeemed hooker, before moving to Switzerland in 1962.
Much of 1963's hit film The Pink Panther was shot in Europe. A crime comedy that led to a number of sequels, the film starred David Niven and Peter Sellers along with Capucine. The risqué comedy What's New Pussycat? (1965), which co-starred Sellers and Peter O'Toole, was filmed entirely in France. She continued making films in Europe until her death.
She met Pierre Trabaud on the set of Rendez-vous (1949) and they married the next year. The marriage lasted only eight months and Capucine never married again.
She had an affair with Charles K. Feldman, who produced her films What's New Pussycat?, The 7th Dawn and The Honey Pot.
Capucine met actor William Holden in the early 1960s. They starred in the films The Lion (1962) and The 7th Dawn (1964). Holden was married to Brenda Marshall, but the two began a two-year affair. After the affair ended, she and Holden remained friends until Holden's death in 1981.
On 17 March 1990, Capucine jumped to her death from her eighth-floor apartment in Lausanne, Switzerland, where she had lived for 28 years, having reportedly suffered from illness and depression for some time.