Afognak Island (Alutiiq: Agw'aneq; ) is an island in the Kodiak Archipelago 5 km north of Kodiak Island in the U.S. state of Alaska. It is 43 mi long from east to west and 23 mi wide from north to south and has a land area of 1,812.58 km2, making it the 18th largest island in the United States.