Alaska is one of the two states that is not bordered by another US state, Hawaii being the other. It is the only state that both is in North America and is not part of the 48 contiguous states; about 500 miles (800 km) of Canadian territory separate Alaska from Washington. Therefore, Alaska is an exclave of the United States that is part of the continental U.S. but is not part of the contiguous U.S. It is also the only mainland state whose capital city is accessible only via ship or air. There are no roads connecting Juneau to the rest of the state.

It is bordered by Yukon Territory and British Columbia, Canada to the east, the Gulf of Alaska and the Pacific Ocean to the south, the Bering Sea, Bering Strait, and Chukchi Sea to the west, and the Beaufort Sea and the Arctic Ocean to the north. Alaska is the largest state by area in the United States. It is larger in area than all but 18 of the world's nations.

Alaska is the largest state in the United States in terms of land area, 570,374 square miles (1,477,261 km²). In fact, it covers more than twice as much land than the next largest state, Texas. If a map of Alaska were superimposed upon a map of the Continental United States, Alaska would overlap Texas, Oklahoma, Kansas, New Mexico and Colorado. Alaska has the longest coastline of any state.