thumb|200px|South tower of Laon Cathedral, where Du Mage worked from 1710 to 1719
Pierre Du Mage (also Dumage; baptised 23 November 1674 – 2 October 1751) was a French Baroque organist and composer. His first music teacher was most likely his father, who was the organist at Beauvais Cathedral. At some point during his youth, Du Mage moved to Paris and studied under Louis Marchand. He also befriended Nicolas Lebègue, who in 1703 procured for him a position as the organist of the Collegiate Church of Saint-Quentin. In 1710, Du Mage was appointed the titular organist of Laon Cathedral. Due to strained relations with his superiors in the cathedral chapter, Du Mage left on 30 March 1719, at the age of 45, and became a civil servant. He apparently neither played nor composed music professionally until his death.
Du Mage's only surviving work is , published in 1708. This collection is dedicated to the chapter of Saint Quentin. It contains a single , comprising eight pieces in the traditional French forms: , , , , , , and . In the brief preface to the collection, Du Mage explains that these are his first works, modelled after the music of his former teacher Marchand. His music is, however, of very high quality,