Amatignak Island is a member of the Delarof Islands (west of the Andreanof Islands), in Alaska's Aleutian archipelago. The south-most point of Alaska and the highest western longitude of the United States are on this island.

The island is about 8 km (5 mi) long north-to-south, and about 4 km (3 mi) wide east-to-west. The nearest island is Ulak Island about 6 km (4 mi) to the northwest.

islands of Alaska