Belle de Jour is Catherine Deneuve at her classic best: beautiful, elegant, cold - and lustful. She plays an upper-class Parisian housewife, Séverine Serizy, whose porcelain perfection hides a cracked soul. We see that already at the start of the film: at the order of her husband she is tied up and whipped by two coachmen, and her face shows sheer ecstasy. Of course this not really happening, but just a kinky daydream - one of the many masochistic fantasies Séverine suffers from. Her husband Pierre (Jean Sorel) is a busy and kindhearted surgeon, but the frigid Séverine is unable to feel passion for him - although she loves him dearly. And the spoiled lady has too much time on her hands...
To make her bondage fantasies more concrete, she starts acting them out by secretly spending her idle afternoons working in a boutique bordello. That, by the way, is also what the film title refers to: "Belle de Jour" is a daylily (literally: "daylight beauty") that blooms only during the day, but the same French term can also refer to a prostitute whose trade is conducted during the daytime. So while remaining chaste in her marriage, in the afternoons from 14:00 to 17:00 Séverine satisfies the weird fetishes of the men that visit the high-class brothel run by Madame Anaïs (Geneviève Page).
Her clients include a fat industrialist, a professor who dresses in role playing costumes and then abuses her, and a duke who likes to enact a mourning scene in a coffin. But she also meets a mean-looking, young gangster (Pierre Clementi) whose cruelty and ugliness rather please her and that is where things go horribly wrong: he falls in love with her, stalks her to her home and finally shoots her husband. Dream and reality have become mixed up with dire consequences.
The end of the film comes as a shock: Pierre has survived the attack but has become an invalid in a wheelchair, which makes Séverine infinitely happy: now she has a task in life, caring for her blind husband. Or is that just another daydream? Several possibilities are left open.
As is usually the case with Bunuel, this surreal, erotic tale forms a gentle criticism of the mores of decaying upper-class society. Deneuve is the ideal actress for this intricate study of female psychology. Despite that the character she plays revels in debauched desires, she retains a cool, inscrutable dignity, clad as she is in the chicest Yves Saint Laurent finery.
This is the best and most iconic film Bunuel ever made. It won the Golden Lion at the Venice Film Festival in 1967.