Unalaska (Aleut: Iluulux̂) is a city in the Aleutians West Census Area of the Unorganized Borough of the U.S. state of Alaska. Unalaska is located on Unalaska Island and neighboring Amaknak Island in the Aleutian Islands off of mainland Alaska.
The population was 4,283 at the 2000 census; it is estimated to have shrunk to 3,836 by 2007. Almost all of the community's port facilities are on Amaknak Island, better known as Dutch Harbor or just "Dutch". It is the largest fisheries port in the U.S. by volume caught. It includes Dutch Harbor Naval Operating Base and Fort Mears, U.S. Army, a U.S. National Historic Landmark.
Dutch Harbor lies within the city limits of Unalaska and is connected to Unalaska by a bridge. Amaknak Island is home to almost 59 percent of the city's population, although it has less than 3 percent of its land area.