AirDrop is an ad-hoc service in Apple Inc.'s OS X and iOS operating systems, introduced in Mac OS X Lion (OS X 10.7) and iOS 7, that enables the transfer of documents among supported Macintosh computers and iOS devices without using mail or a mass storage device.

An airdrop is a type of airlift, developed during World War II to resupply otherwise inaccessible troops, who themselves may have been airborne forces. In some cases, it is used to refer to the airborne assault itself. Early airdrops were conducted by dropping or pushing padded bundles from aircraft. Later small crates with parachutes were pushed out of the aircraft's side cargo doors. Later cargo aircraft were designed with rear access ramps, lowerable in flight, that allowed large platforms to be rolled out the back.