Pierre-Louis Dumesnil was a French painter who specialized in genre scenes.

Pierre-Louis Dumesnil was born in 1698. He was received into the Académie de Saint-Luc. There he was professor (1748-1773), rector (1773-1775), and then permanent rector (1775-1776). Between 1751 and 1754 his work was shown as each of the seven exhibitions of the institution. Although some of his works were historical, such as Saint Charles Borromée making alms (1741), most were genre scenes. His paintings show the influence of Jean-Baptiste Chardin both in the selection of themes and the composition. A portrait of Dumesnil by Madame Vigée-Lebrun , created in 1774 on the occasion of her reception into the Académie de Saint-Luc, has unfortunately been lost.