The Thomas-Morse O-19 was an American observation biplane built by the Thomas-Morse Aircraft Company for the United States Army Air Corps.

The O-19 was based on the earlier Thomas-Morse O-6 biplane.

It was a conventional two-seat biplane of metal construction with fabric-covered wings and tail surfaces.

The design was evaluated with a number of different engine installations and the type was ordered into production as the O-19B with a Pratt & Whitney R-1340-7 Wasp radial engine.

Data from The Illustrated Encyclopedia of Aircraft (Part Work 1982-1985), 1985, Orbis Publishing, Page 3000General characteristics Performance Armament