Eastern North Pacific species of the fathead sculpin genus Malacocottus Bean are assessed following examination of over 300 specimens collected from throughout the known range of the genus, from the west coast of North America around the Pacific Rim to Japan, including the marginal waters of the Salish Sea, Bering Sea, Sea of Okhotsk, and Sea of Japan. The results of this study demonstrate that two species of Malacocottus occur in the eastern North Pacific. Malacocottus zonurus is found in the North Pacific from Washington State around the Pacific Rim to Japan, and in all marginal seas. Malacocottus kincaidi Gilbert and Thompson is apparently endemic to the Salish Sea, known only from Puget Sound and the Strait of Georgia. These two species differ in preopercular spine morphology and gill-raker counts. Malacocottus aleuticus Smith, based on a single juvenile specimen, is a synonym of M. zonurus. This study includes redescriptions of M. zonurus and M. kincaidi, comparisons of both species with M. gibber, and a key to the three known species of the genus.