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.
Specialized armed helicopters fly from ships at sea, and are equipped for antisubmarine warfare or strikes with anti-shipping missiles.
Direct fire support delivered by weapons mounted on helicopters began informally in the Korean War, with United States Marines firing their weapons from the open doors of the aircraft, into the treeline of the landing area below. The concept evolved with the French during the Algerian and the First Indochina wars, in the form of armed helicopters; where utility, cargo, and observation military helicopters were modified to carry various weapons.