A flight is a small military unit within the larger structure of an air force, naval air service, or army air corps; and is usually subservient of a larger squadron. A military aircraft flight is typically composed of four aircraft, though two to six aircraft may also form an aircraft flight; along with their aircrews and ground staff. In some very specific examples, typically involving historic aircraft, a flight may contain as many as twelve aircraft, as is the case with the Battle of Britain Memorial Flight (BBMF) of the British Royal Air Force (RAF). In most usages, two or more flights make up a squadron. Foreign languages equivalents include escadrille (French), escuadrilla (Spanish), esquadrilha (Portuguese), zveno (Russian), and Schwarm (German).

In the case of a non-flying, or 'ground flight', such as Mechanical Transport Flight (MTF), Supply Flight, Accounts Flight, etc; no aircraft, and a roughly equivalent number of support personnel may be utilised.

The term 'flight' is also a basic unit for intercontinental ballistic missiles (ICBMs).