Mézeray was appointed to a committee that supervised La Gazette.
Mézeray won the favor of Pierre Séguier and was given the title "Historiographer to the King of France". In 1649, on the death of Vincent Voiture, he was admitted to the Académie française. His Abrégé chronologique (3 vols., 1667–1668) went through fifteen editions between 1668 and 1717; and he used it to attack the financiers, with the result that his salary as historiographer was diminished by Colbert.
Mézeray succeeded Valentin Conrart as permanent secretary to the Académie française (1675), and died at Paris. He translated Grotius's Traité de la religion chretienne (1640), and a Histoire des Turcs depuis 1612 jusqu'en 1649 (1650), which is an addition to a continuation of Demetrius Chalcondyles.