Atka Island is an island in the Andreanof Islands of the Aleutian Islands of Alaska, at . The island is 80 km (50 miles) east of Adak Island. The island is 105 km (65 miles) wide and 3-32 km (2-20 miles) wide. The northeast of Atka Island contains a volcano.

The village of Atka, Alaska is on the east side of the island. A United States Air Force base, established during World War II is also on Atka Island.