Portrait by Jean-Marc Nattier, ca. 1730
Louise-Marie-Madeleine Guillaume de Fontaine (after marriage known as Madame Dupin; 28 October 1706 – 20 November 1799) was a French saloniste. A woman of spirit and famous for her beauty, between 1733 and 1782 she hosted a famous literary salon in Paris and owned the Château de Chenonceau, which was known as a center of the most famous French philosophers of the Age of Enlightenment.