The Pratt & Whitney F100 is an afterburning turbofan engine designed and manufactured by Pratt & Whitney to power the U.S. Air Force's "FX" initiative in 1965, which became the F-15 Eagle. The engine was to be developed in tandem with the F401 which shares a similar core but with the fan upscaled for the U.S. Navy's F-14 Tomcat, although the F401 was later abandoned due to costs and reliability issues. The F100 would also power the F-16 Fighting Falcon for the Air Force's Lightweight Fighter (LWF) program.

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.