Jean-Baptiste Massillon, CO (24 June 1663 – 28 September 1742), was a French Catholic prelate and famous preacher who served as Bishop of Clermont from 1717 until his death in Beauregard-l'Évêque.
At the age of eighteen he joined the French Oratory and taught for a time in the colleges of his congregation at Pézenas, and Montbrison and at the Seminary of Vienne.
Massillon enjoyed in the 18th century a reputation equal to that of Jacques-Bénigne Bossuet and of Louis Bourdaloue, and was much praised for his eloquence by Voltaire, D'Alembert and kindred spirits among the Encyclopaedists.
[1] Massillon's popularity was probably because in his sermons he lays little stress on dogmatic questions, but treats generally of moral subjects, in which the secrets of the human heart and the processes of man's reason are described with poetical feeling.
His great literary power, his reputation for benevolence, and his known toleration and dislike of doctrinal disputes caused him to be much more favourably regarded than most churchmen by the philosophers of the 18th century.