Jules Gustave Flammermont (5 February 1852, in Chaumont-en-Vexin – 29 July 1899, in Lille) was a French historian, largely known for his writings on history of the 18th century.
He worked as a librarian and archivist in the town of Senlis, and afterwards served as secretary to the Duke of Aumale at the Château de Chantilly.
In 1883/84 he conducted archival research in Vienna and Berlin, and in 1884 received his doctorate of letters at the Sorbonne.
He successively taught classes in history at the universities of Poitiers (from 1884), Douai (from 1886) and Lille (from 1887).
In 1887 he received the title of professor of history and geography of antiquity and the Middle Ages.