The daughter of a schoolteacher, Fossey was five years old when she was cast by director René Clément to star in his film, Forbidden Games.

[1] 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.

Brigitte Fossey has a daughter from her marriage to director Jean-François Adam, whom she met while making his 1970 film M comme Mathieu [fr].