Louis Phélypeaux (1643–1727), marquis de Phélypeaux (1667), comte de Maurepas (1687), comte de Pontchartrain (1699), known as the chancellor de Pontchartrain, was a French politician. After serving as head of the Parlement of Brittany, he held office as Controller-General of Finances and as Navy Secretary and, from 1690, Secretary of State of the Maison du Roi. Nonetheless, his handling of the French Navy, a powerful force under Colbert and Seignelay, is criticised, and he is considered to be in part responsible for the defeat at the battles of Barfleur and La Hougue in 1692.