Claude-Adrien Nonnotte (b. in Besançon, 29 July 1711; d. there, 3 September 1793) was a French Jesuit controversialist, best known for his writings against Voltaire.
At nineteen he entered the Society of Jesus and preached at Amiens, Versailles, and Turin. When Voltaire began to issue his Essai sur les moeurs (1754), an attack on Christianity, Nonnotte published, anonymously, the Examen critique ou Réfutation du livre des moeurs; and when Voltaire finished his publication (1758), Nonnotte revised his book, which he published at Avignon (2 vols., 1762). He dealt with what he saw as historical and doctrinal errors contained in Voltaire's work. Nonnotte's work reached the sixth edition in 1774. Voltaire retorted in his Eclaircissements historiques, and for twenty years continued to attack Nonnotte.
Nonnotte's publication continued to circulate, and was translated into Italian, German, Polish, and Portuguese. After the suppression of the Jesuits, Nonnotte withdrew to Besançon and in 1779 added a third volume to the Erreurs de Voltaire, namely, L'esprit de Voltaire dans ses écrits, for which it was impossible to obtain the approval of the Paris censor. Against the Dictionnaire philosophique, in which Voltaire had recapitulated all his attacks on Christianity, Nonnotte published the Dictionnaire philosophique de la religion (Avignon, 1772), in which he replied to all the objections then brought against religion. The work was translated into Italian and German.
Towards the end of his life Nonnotte published Les philosophes des trois premiers siècles (Paris, 1789), in which he contrasted the ancient and the modern philosophers. The work was translated into German. He also wrote Lettre à un ami sur les honnêtetés littéraires (Paris, 1766), and Réponse aux Éclaircissements historiques et aux additions de Voltaire (Paris, 1774). These publications obtained for their author a eulogistic Brief from Clement XIII (1768), and the congratulations of St. Alphonsus Liguori, who declared that he had always at hand his "golden works" in which the chief truths of the Faith were defended with learning and propriety against the objections of Voltaire and his friends. Nonnotte was also the author of L'emploi de l'argent (Avignon, 1787), translated from Maffei; Le gouvernement des paroisses (posthumous, Paris, 1802). All were published under the title Oeuvres de Nonnotte (Besançon, 1819).