Pierre-Benjamin Dumoulin (ca 1799 – September 24, 1856) was a seigneur, lawyer, judge and political figure in Lower Canada and Canada East. He was probably born in Trois-Rivières, Lower Canada around 1799 and studied at the Séminaire de Nicolet. He articled in law at Trois-Rivières with Pierre Vézina, was admitted to the bar in 1821 and set up practice in Trois-Rivières. He acquired part of the seigneury of Grosbois-Est during the 1820s. In 1826, he ran unsuccessfully in a by-election to represent Saint-Maurice in the Legislative Assembly of Lower Canada; he was elected in 1827 for Trois-Rivières, reelected in 1830 and resigned in 1832. He was named a Queen's Counsel and justice of the peace in 1838. Following a complaint against him by Colonel Bartholomew Conrad Augustus Gugy, he was remo