Marie Louise Mignot (February 12, 1712 – August 10, 1790) was a French literary figure.

She was the daughter of Voltaire's sister, Catherine Arouet (1686–1726) and her husband Pierre-François Mignot (d. 1737).

After the death of her widowed father in 1737, Voltaire provided her with a dowry and she married army supply officer Nicolas-Charles Denis, giving rise to her married name of Madame Denis.

[1] After her husband's premature death in 1744, she was taken in by her uncle Voltaire and became his housekeeper, hostess and companion.

She also adopted his protégée Reine Philiberte de Varicourt when the latter's marriage to the Charles, marquis de Villette foundered on his homosexuality.