Cargo aircraft transport all types of freight instead of passengers. The aircraft are either built as cargo aircraft or converted from a former passenger aircraft. In addition to the cargo hold, i.e. the absence of seats, the cargo aircraft is usually fitted with larger doors so that the cargo can be loaded or unloaded using special forklifts or other equipment. Cargo aircraft are used by freight companies, private individuals, federal authorities and the armed forces.

The first cargo planes were used for mail delivery in 1911. At that time, aircraft were often not yet used purely as cargo planes. In the early 1920s, soldiers and material were transported by the British Army to the Middle East via the fast air route.