Guided missile, flying weapon that can alter its course during flight toward a target. It usually consists of a rocketlike body containing a rocket or jet engine and an explosive warhead. The length of a guided missile may range from 4 ft (1.2 m) to 60 ft (18 m). Its course may be controlled by instruments in the missile itself or by a crew operating ground controls. Guided missiles are commonly classified as surface-to-surface, surface-to-air, air-to-air, and air-to-surface.
They can be fired from permanent or mobile launchers, from ships and submarines, and from airplanes. Though unguided rockets were first developed by the Chinese in the 13th century and used by the British in war during the 19th century, the first guided missiles used in combat were developed by Germany during World War II. Since then, the United States and the former USSR have been leading developers of guided missiles.