Maurepas's father was a secretary of state under King Louis XIV. In 1718 Maurepas was made secretary of state for the king's household, thereby gaining authority over ecclesiastical affairs and the administration of Paris. Appointed to the additional office of secretary for the marine in 1723, he undertook the immense task of reorganizing the severely demoralized French navy.

Maurepas remained in office until 1749, when, as a result of a personal quarrel with Louis XV's mistress, Madame de Pompadour, he was disgraced and banished to his estates. In 1774 he was recalled from exile and made chief adviser to the newly crowned young monarch, Louis XVI. Maurepas proved unwilling to continue the reforming trend that had begun with the abolition of the political powers of the Parlements (high courts of justice) in 1771, and he persuaded Louis to restore the full authority of the Parlements (1774), which sought to protect the interests of the nobles and the wealthy bourgeoisie. Although Maurepas secured the appointment of Anne-Robert Turgot as controller general of the finances, he refused to support Turgot's efforts to shift the burden of taxation to the privileged orders. In 1776 he persuaded Louis to dismiss Turgot. Maurepas then had Jacques Necker put in charge of government finances, but he became jealous of Necker's popularity and forced him to resign in 1781.