A new species of the skate genus Bathyraja, Bathyraja mariposa, is described from the Aleutian Islands and its geographic and bathymetric range documented. Bathyraja mariposa is similar to Bathyraja violacea and Rhinoraja taranetzi in its moderate maximum size and absence of thorns on the disc. However, it can be clearly distinguished from B. violacea by its distinctive color pattern, uniform covering of fine denticles, and clasper morphology. It can be distinguished from R. taranetzi and other similar western North Pacific species by the lack of a pseudosiphon on the clasper as well as by differences in various morphometric and meristic characters.