The Pratt & Whitney R-1690 Hornet was a widely used American aircraft engine. Developed by Pratt & Whitney, 2,944 were produced from 1926 through 1942. It first flew in 1927. It was a single-row, 9-cylinder air-cooled radial design. Displacement was 1,690 cubic inches. It was built under license in Italy as the Fiat A.59. In Germany, the BMW 132 was a developed version of this engine. The R-1860 Hornet B was an enlarged version produced from 1929.

Pratt & Whitney is an American aerospace manufacturer with global service operations. It is a subsidiary of RTX Corporation. Pratt & Whitney's aircraft engines are widely used in both civil aviation and military aviation. Its headquarters are in East Hartford, Connecticut. The company is the world's second largest commercial aircraft engine manufacturer, with a 35% market share as of 2020. In addition to aircraft engines, Pratt & Whitney manufactures gas turbine engines for industrial use, marine propulsion, and power generation. In 2017, the company reported that it supported more than 11,000 customers in 180 countries around the world.