In 1967, at age twenty, after studying acting at Yves Furet "Studio d'Entrainement de l'Acteur" in Paris, Fossey was offered the female lead by director Jean-Gabriel Albicocco for his film "Le Grand Meaulnes". As an adult Fossey acted both on stage and in film, working with French directors such as François Truffaut and Bertrand Blier. Fluent in English, Fossey has appeared in several Hollywood motion pictures, including a 1979 role as the wife of Paul Newman in the Robert Altman-directed film, "Quintet". In 1982, she was a member of the jury at the 32nd Berlin International Film Festival. During the 1990s, she began performing in television productions.