Jacques-Louis Dumesnil (French pronunciation: [ʒak lwi dymenil]; 15 March 1882, in Paris – 15 June 1956, in Paris) was a French politician.
From an old Seine-et-Marne family, he initially worked as a journalist and lawyer at the Cour de Paris.
He was elected a conseiller général for Seine-et-Marne aged 25 and a radical deputy for Seine-et-Marne aged 28 in 1910.
He was mobilised for the First World War as a sous-lieutenant.
During the course of the conflict he rose to lieutenant then captain, was wounded at the First Battle of the Marne and won the Légion d'honneur and the Croix de Guerre.