[2] Icelinus borealis was first formally described in 1896 by the American ichthyologist Charles Henry Gilbert with its type locality given as north and south of the Aleutians and from Bristol Bay in Alaska.

[1] The specific name borealis means "northern" and is a reference to the description of this species based on a type locality of Alaska.

The overall color is dark olive gray or brown on the upper body, paler below.

[2] Icelinus borealis is found in the temperate eastern Pacific Ocean from the Bering Sea coast of Alaska south as far as Puget Sound, in Washington.

[2] This species is common in waters near to rookeries of Steller's sea lions (Eumetopias jubatus) and so constitute part of the diverse prey hunted by that mammal.