Madame X or Portrait of Madame X is the title of a portrait painting by John Singer Sargent of a young socialite named Virginie Amélie Avegno Gautreau, wife of the French banker Pierre Gautreau. Madame X was painted not as a commission, but at the request of Sargent. It is a study in opposition. Sargent shows a woman posing in a black satin dress with jeweled straps, a dress that reveals and hides at the same time. The portrait is characterized by the pale flesh tone of the subject contrasted against a dark colored dress and background.
The scandal resulting from the painting's controversial reception at the Paris Salon of 1884 amounted to a temporary set-back to Sargent while in France, though it may have helped him later establish a successful career in Britain and America.