Marie Nicolas Sylvestre Guillon (January 1, 1760, Paris – October 16, 1847, Montfermeil), was a French ecclesiastic, and librarian.
He was a librarian and almoner in the household of the princesse de Lamballe.
A man of facile conscience, he afterward served in turn under Napoleon, the House of Bourbon and the House of Orléans and became canon of St Denis, bishop of Morocco and dean of the Sorbonne.
In May 1831, he administered Extreme Unction to the republican Abbé Grégoire despite the opposition of Hyacinthe-Louis de Quélen, Archbishop of Paris.
[1] Among his many literary works were a Collection, des brefs du pape Pie VI (1798), Bibliothèque choisie des Pères de l'Église grecque et latine (1822–28, 26 vols.