The Vought O5U was a 1930s prototype American observation floatplane to meet a United States Navy requirement for a catapult launched scouting aircraft.

The contract was won by Curtiss who went on to produce the SOC Seagull; only one O5U was built.

[1] The United States Navy contracted three companies to produce prototypes to meet a requirement for a catapult launched biplane, with a central float and folding wings.

The XO5U-1 (serial number 9399) was powered by a single Pratt & Whitney R-1340-12 piston engine[2] and first flew on the 8 May 1934.

The Status of Naval Aircraft, dated June 1937, listed the XO5U-1 as assigned at Mustin Field at the Naval Aircraft Factory, Philadelphia, Pennsylvania.