Ménageot was born in London, the son of Augustin Ménageot (d 1784), an art dealer and adviser to Denis Diderot. François-Guillaume trained under first Jean-Baptiste-Henri Deshays, then Joseph-Marie Vien, and finally François Boucher (1703–1770), in his early works adopting the latter's style and use of warm, light colours. His 1766 Tomyris Plunging the Head of Cyrus into a Bowl of Blood (Paris, Ecole Normale Supérieure des Beaux-Arts) won the Prix de Rome and a stay at the French Academy in Rome from 1769 to 1774.