Born in Angers on October 30, 1843, he belonged to the nobility of Saumur. After studying law, he became a student of Antoine Louis Barye, exhibited his sculptures at the Salon des Champs-Elysees and wrote several plays. His publications mainly focus on Gallo-Roman history and archaeology.
Member of the Société Artistique de l'Ouest, the Société d'émulation des Côtes du Nord, the Société d'Anthropologie de Peers and the Société des Traditions Populaires, he published numerous articles in the Revue des Traditions Populaires. A founding member in 1904 of the Société Préhistoire de France, Lionel Bonnemère constituted an important collection of amulets and popular jewelry which will enrich the funds of the Museum of Popular Arts and Traditions. He died in Paris on November 28, 1905.