Pierre Clémenti (28 September 1942 – 27 December 1999) was a French actor.

Born in Paris, Clémenti studied drama and began his acting career in the theatre. He secured his first minor screen roles in 1960 in Yves Allégret's Chien de pique performing alongside Eddie Constantine. Arguably, his most famous role was that of gangster lover of bourgeois prostitute Catherine Deneuve in Belle de jour, the 1967 classic by Luis Buñuel, in whose film La voie lactée he played the Devil. He appeared in several highly regarded films of the period, working with many of Europe's best known directors, including Luchino Visconti (The Leopard), Pier Paolo Pasolini (Pigsty) and Bernardo Bertolucci (The Conformist and Partner). Other directors he has worked with are Liliana Cavani, Glauber Rocha, Miklós Jancsó and Philippe Garrel.