Marie Louise Mignot (1712–1790) was a French literary figure. She was the daughter of Voltaire's sister, marrying his material aid Denis in 1737, giving rise to her married name of Madame Denis. After her husband's premature death in 1744, she was taken in by Voltaire and became his housekeeper, hostess and companion. She also adopted his protégée Reine Philiberte de Varicourt when the latter's marriage to the marquis de Villette foundered on his homosexuality.
She refused to follow Voltaire to the court of Frederick II of Prussia and only re-joined him at Ferney, where they lived as a married couple (though Voltaire was in love with her, they never married) until Voltaire's death in 1778, on which she inherited the majority of his estate. However, preferring Paris society, she sold off the chateau to move back to Paris.