Léon Hennique was born in Basse-Terre, Guadeloupe on 4 November 1850. At the age of nine he moved to France where he received much of his formal education. He received educational training in Brest and Saint Quentin, and from 1865 to 1869 in Paris at the Jesuit school de la rue de Vaugirard. Hennique tried his hand at painting but did not find it as rewarding as writing. He was a novelist, playwright, journalist and a man of letters. His first published work appeared on 20 March 1876 in The Republic of Letters. Hennique followed the Naturalist school of thought, contributing several works to this literary movement.
Hennique was a close friend and associate of Emile Zola and the brothers Goncourt. He was a member of the Group of Médan presided over by Zola. Hennique assumed the presidency of the Goncourt academy from 1907 to 1912. He was also involved in developments in the Théatre-Libre in Paris. He was named a Chevalier de la Légion d'Honneur in 1895 and was also named an Officer of the National Order.