Atka is a small city located on the east side of Atka Island, in Aleutians West Census Area, Alaska, United States. The population was 53 at the 2020 census, down from 61 in 2010.

Atka Island is the largest island in the Andreanof Islands of the Aleutian Islands of Alaska. The island is 50 miles (80 km) east of Adak Island. It is 65 miles (105 km) long and 2–20 miles (3–30 km) wide with a land area of 404.6 square miles (1,048 km2), making it the 22nd largest island in the United States. The northeast of Atka Island contains the Korovin volcano which reaches a peak of 5,030 feet (1,533 m). Oglodak Island is located 3.4 miles off Cape Kigun, Atka's westernmost point.