Achchyon (Russian: Аччён; Chukot: А’чон; Central Siberian Yupik: Асун),[1] is a lake in Providensky District, Chukotka Autonomous Okrug, Russian Federation.

The nearest inhabited place is Nunligran village, located nearly 20 km (12 mi) to the west.

During severe storms in the Bering Sea, the waves break over the landspit and large amounts of seawater spill into the lake.

However, there are four rivers —Ergytgyn, Likvylenveem, Kuyulvayam and Keperveem, as well as fourteen unnamed streams that flow into Achchyon.

In the 1950s, salmon production reached 50 metric tons, but catches have plummeted since the end of the 20th century.