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 (249 hp) Isotta-Fraschini V.6.

The observer had a single ring-mounted 7.7 mm (0.303 in) machine gun.

A sole S.57bis (improved) was built, with a 224 kW (300 hp) Hispano-Suiza Type 42 engine.

Data from The complete encyclopedia of world aircraft [1]General characteristics Performance Armament