The Canon de 155 C modèle 1917 Schneider, often abbreviated as the C17S, was a French howitzer designed by Schneider. It was essentially the Canon de 155 C modèle 1915 Schneider fitted with a different breech to use bagged propellant rather than the cartridge cases used by the older howitzer. It was used by France, Italy, Russian Empire, Belgium and the United States from 1917 during World War I and was widely exported after the war. Surviving weapons were in service with France, Poland, Greece, Italy, Belgium, the United States and Finland during World War II. Captured weapons were used by the Germans for their 2nd-line artillery and coast defense units.