La Sirène du Mississipi (Mississippi Mermaid)

Screenplay: François Truffaut, adapted from William Irish’s novel Waltz into Darkness
Music: Antoine Duhamel
Costumes: Yves Saint Laurent for Catherine Deneuve
Cast: Jean-Paul Belmondo, Catherine Deneuve, Michel Bouquet, Nelly Borgeaud, Martine Ferrière, Marcel Berbert, Yves Drouhet, and Roland Thénot

After dressing Catherine Deneuve for Belle de Jour and La Chamade (Heartbeat), Yves Saint Laurent designed a less innocent and more masculine wardrobe for her character in La Sirène du Mississipi (Mississippi Mermaid). In the film, Deneuve plays an undeniably powerful femme fatale. Her outfits were taken from the SAINT LAURENT rive gauche Spring-Summer 1968 collection. 

Of all the major couturiers, he is the biggest cinephile; he understood what film costumes were supposed to be and was able to conceive them in a way that could be adapted to different movements and styles.

François Truffaut.