The Savoia-Marchetti S.57 was an Italian single-engine biplane flying boat intended for aerial reconnaissance built by Savoia-Marchetti for Regia Aeronautica after World War I. Of wooden construction with a single-step hull with pilot and observer-gunner in tandem open cockpits in the bow the S.57 was powered by a single 186 kW (250 hp) Isotta-Fraschini V6. The observer had a single ring-mounted 7.7 mm (.303 in) FIAT machine gun.
Made by SIAI-Marchetti.