The son of the renowned French sculptor Paul Belmondo, he studied at Conservatoire National Superieur d'Art Dramatique (CNSAD); after the minor stage performances he made his screen debut in À pied, à cheval et en voiture (1957). However, the breakthrough role in Jean-Luc Godard's Breathless (1960) made him one of the key figures in the Nouvelle Vaugue.