An attack helicopter is an armed helicopter with the primary role of an attack aircraft, with the offensive capability of engaging ground targets such as enemy infantry, military vehicles and fortifications. Due to their heavy armament they are sometimes called helicopter gunships.

An armed helicopter is a military helicopter equipped with aircraft ordnance. Most commonly, it is used for attacking targets on the ground. Such a helicopter could be either purposely designed for a ground-attack mission—in which case it would be more specifically categorized as an attack helicopter—or may have been previously designed for other uses, such as utility, air cargo, aerial reconnaissance, etc., with the weapons mounts being modifications, rather than part of the design of the helicopter. The purpose of the modification to an armed helicopter configuration can be field expediency during combat, the lack of military funding to develop or purchase attack helicopters, or the need to maintain the helicopter for missions that do not require the weapons.