Pierre Mandonnet (26 February 1858, Beaumont, Puy-de-Dôme – 4 January 1936, Le Saulchoir, Belgium) was a French-born, Belgian Dominican historian, important in the neo-Thomist trend of historiography and the recovery of medieval philosophy.
He made his reputation with a study of Siger of Brabant.In 1887 he was ordained as a priest, and from 1891 to 1919, was a professor of church history at the University of Fribourg.