The Grumman F3F is a biplane fighter aircraft produced by the Grumman aircraft for the United States Navy during the mid-1930s. Designed as an improvement on the F2F, it entered service in 1936 as the last biplane to be delivered to any American military air arm. It was retired from front line squadrons at the end of 1941 before it could serve in World War II, and replaced by the Brewster F2A Buffalo. The F3F, which inherited the Leroy Grumman-designed retractable main landing gear configuration first used on the Grumman FF, served as the basis for a biplane design ultimately developed into the much more successful F4F Wildcat that succeeded the subpar Buffalo.