Eubranchus steinbecki is a species of sea slug or nudibranch, a marine gastropod mollusc in the family Eubranchidae.

[2] This species was described from specimens collected from boat floats at Dana Landing, Mission Bay, San Diego, 32°42′N 117°33′W / 32.700°N 117.550°W / 32.700; -117.550 and intertidally at Palos Verdes, 34°00′N 118°47′W / 34.000°N 118.783°W / 34.000; -118.783, California, United States.

[1] It has been reported from Palos Verdes south to La Paz, Baja California Sur, Mexico.

[3]