Nicolas Lemercier or Le Mercier (1541 – 1637) was a French architect or master mason. He was the son of architect/mason Pierre Lemercier and may have been the father of Jacques Lemercier although there is no proof. Works attributed to Nicolas include Pontoise Cathedral and the nave of the church of Saint-Eustache, Paris. He was succeeded at Saint-Eustache by his son-in-law Charles David, who married Nicolas' daughter Anne.[1][2]