Painter, engraver, illustrator, decorator. Jos Léonard was open to various influences ranging from cubism to futurism prior to, in 1918, coming into contact with the Antwerp avant-garde, where together with Jozef Peeters and others founds the Kring Modern Kunst. In 1919 he takes part in the group's first exhibition, and shows his first abstract works the following year. He also contributes to the review Het overzicht, and participates at the international exhibition of the second Kongres voor Moderne Kunst in Antwerpen in 1920. In 1925 he starts a career in advertising illustration, a discipline he will also later teach at Antwerp's Vocational School for Applied Arts.