The World War II Allied names for Japanese aircraft were reporting names, often described as codenames, given by Allied personnel to Imperial Japanese aircraft during the Pacific campaign of World War II. The names were used by Allied personnel to identify aircraft operated by the Japanese for reporting and descriptive purposes. Generally, Western men's names were given to fighter aircraft, women's names to bombers, transports, and reconnaissance aircraft, bird names to gliders, and tree names to trainer aircraft.

The Mitsubishi G4M is a twin-engine, land-based medium bomber formerly manufactured by the Mitsubishi Aircraft Company, a part of Mitsubishi Heavy Industries, and operated by the Imperial Japanese Navy from 1940 to 1945. Its official designation is Mitsubishi Navy Type 1 attack bomber and was commonly referred to by Japanese Navy pilots as Hamaki due to the cylindrical shape of its fuselage and its tendency to ignite after a hit. The Allied reporting name was "Betty".