An amphibious assault ship (also referred to as a commando carrier[note 1] or an amphibious assault carrier) is a type of amphibious warfare ship employed to land and support ground forces on enemy territory by an amphibious assault. The design evolved from aircraft carriers converted for use as helicopter carriers, but includes support for amphibious landing craft, with most designs including a well deck, the common large flight deck design coming full circle some amphibious assault ships now have a secondary role as aircraft carriers.
The role of the amphibious assault ship is fundamentally different from a standard aircraft carrier: its aviation facilities have the primary role of hosting helicopters to support forces ashore rather than to support strike aircraft. However, some are capable of serving in the sea-control role, embarking aircraft like Harrier fighters for CAP and ASW helicopters or operating as a safe base for large numbers of STOVL fighters conducting air support for the MEU once it has gone ashore. Most of these ships can also carry or support landing craft, such as air-cushioned landing craft (hovercraft) or LCUs.
The largest fleet of these types is operated by the United States Navy, including the Tarawa class dating back to the 1970s and the larger Wasp class ships that debuted in 1989. Amphibious assault ships are also operated by the British Royal Navy, the French Navy, the Italian Navy, the Republic of Korea Navy, and the Spanish Navy.
Although the term amphibious assault ship is often used interchangeably with the more-general term amphibious warfare ship, it specifically applies only to large-deck amphibious ships such as the LPH, LHA, and LHD types. This does not include the amphibious transport dock (LPD), and dock landing ship (LSD).