Léonard Misonne was born to a wealthy family of the Charleroi area and lived in the family home until his death. He studied classics and later earned a degree in engineering before choosing photography as his vocation in 1896. He was a member of the Société Française de Photographie and was a founding member of the Cercle d'Art Photographique. His work was admired by the pictorialists and was included in exhibitions in Europe and the United States from the late 1890s to the 1920s. His book Tableaux Photographiques was published in 1927.