Marie-Justine-Benoîte Favart (née Marie Duronceray) (June 15, 1727 – April 22, 1772) was an opera singer, actress, and dancer, the wife of the dramatist, Charles Simon Favart.
To her is largely due the beginnings of the change in this theatre to performances of a lyric type adapted from Italian models, which developed later into the genuine French comic opera. She was also a bold reformer in matters of stage costume, playing the peasant with bare arms, in wooden shoes and linen dress, and not, as heretofore, in court costume with enormous hoops, diamonds and long white kid gloves. With her husband, and other authors, she collaborated in a number of successful pieces, and one La fille mal gardée she produced alone.
Maurice, comte de Saxe, a marshal of France and her husband's patron, began to make advances to Mme Favart, and Favart was forced to flee. Mme Favart was established by the marshal in a house at Vaugirard; proving a fickle mistress, she was suddenly arrested and confined in a convent, where she was brought to unconditional surrender in the beginning of 1750. Before the year was out the marshal died, and Mme Favart reappeared at the Comédie Italienne, where for twenty years she was a great favourite. Among the roles created by Mme Favart was the heroine of Egidio Duni's La fée Urgèle.
Madame Favart in fictionalised form is the title-character of Offenbach's 1878 opéra comique, Madame Favart.