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

Weapons used on attack helicopters can include autocannons, machine guns, rockets, and guided anti-tank missiles such as the Hellfire. Many attack helicopters are also capable of carrying air-to-air missiles, though mostly for purposes of self-defense. Today's attack helicopter has two main roles: first, to provide direct and accurate close air support for ground troops, and the second, in the anti-tank role to destroy enemy armor concentrations. Attack helicopters are also used to supplement lighter helicopters in the armed scout role. In combat, an attack helicopter is projected to destroy around 17 times its own production cost before it is destroyed.