The St. Louis YPT-15 was an American two-seat primary training biplane, built by the St. Louis Aircraft Corporation for use by the United States Army Air Corps.

The PT-15 was a development of the "off-the-shelf" PT-1W for use by the U.S. Army Air Corps, ordered for stop-gap duty in the training of airmen in the build-up to World War II.

A single Wright R-760 radial engine of 220 horsepower (160 kW) provided power.

[1] One prototype PT-1 crashed at Wright field trials on 23 May 1936 bearing the serial number of an older design, the St. Louis PT-35[2] All thirteen examples of the YPT-15 were locally assigned (as PT-15s) to Parks College Civilian Pilot Training Program.

It is located at the Western Antique Aeroplane & Automobile Museum in Hood River, Oregon and is maintained in airworthy condition.