The morphological and distributional limits of Liparis liparis (Linnaeus) have been ill defined since the original description. The resulting confusion has prevented a clear understanding of the taxonomy of Arctic and North Atlantic Liparis. An examination of over 900 specimens from Arctic and eastern North Atlantic waters has led to the following conclusions. First, the taxonomy of these forms can usually be resolved with complete counts of fin rays, vertebrae, pyloric caeca, and selected morphometric characters. Second, there are three species from the Arctic that have been confused with L. liparis. Two of these, L. fabricii Kroyer and L. tunicatus Reinhardt, are circumpolar. The third species, L. gibbus Bean, is a low-Arctic form that may be excluded from much of the Soviet Arctic. Third, L. liparis is restricted to the eastern North Atlantic where it is found from northern Norway south to around Great Britain and into the North and Baltic seas. A key to the 10 nominal species from North Atlantic and Arctic waters is included.