Cazin grew up in Boulogne-sur-Mer. By 1862 or 1863 he had moved to Paris. He studied under Lecoq de Boisbaudran at the Petite Ecole where he met Fantin-Latour, Legros and Lhermitte. In the mid-1860s he taught at the Ecole Spéciale de l'Architecture in Paris, and in 1868 became director of the Ecole de Dessin in Tours. In 1871 he moved to England, where he designed pottery for Fulham Pottery. In 1875 he returned to France, settling in Equihen near Boulogne-sur-Mer. From 1884 to 1888 he travelled in Italy and Holland. His later paintings were mainly landscapes.