Portrait of Madame X is the informal title of a portrait painting by John Singer Sargent of a young socialite named Virginie Amélie Avegno Gautreau, wife of Pierre Gautreau.
The model was an American expatriate who married a French banker, and became notorious in Parisian high society for her beauty and rumored infidelities. She wore lavender powder and prided herself on her appearance.
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.
For Sargent, the scandal resulting from the painting's controversial reception at the Paris Salon of 1884 amounted to the failure of a strategy to build a long-term career as a portrait painter in France, though it may have helped him establish a successful career in Britain and America.