The butter sole (Isopsetta isolepis) is an edible flatfish of the family Pleuronectidae.

It is a demersal fish that lives on soft, silty bottoms in temperate waters at depths between 20 and 425 m (66 and 1,394 ft).

Its native habitat is the northeastern Pacific, from the Bering Sea and the Aleutian Islands, along the coasts of Alaska, Canada, and the USA as far south as Ventura, California.

Its upper side is light to dark or greyish brown, with yellow or green mottling; its underside is white.

[2] The butter sole's diet consists of benthic organisms such as crabs, shrimp, worms, and sand dollars, as well as young herring.