Many species of the family Echinorhinidae are reported from the Cenozoic, but from the Cretaceous only a few species have been reported. In this paper, a new species, Echinorhinus wadanohanaensis of the family Echinorhinidae, is described from the Upper Cretaceous (Santonian) Hinoshima Formation of the Himenoura Group at Ryugatake-machi in Kumamoto Prefecture, Japan. The species differs from other congeners in having a distally inclined main cusp, the distally directed cusp apex not extending beyond the distal demarcation of the distal heel, no lateral cusplets (basal cusplets), a large principal cusp, no vertical groove in the root, few grooves below the boundary of the enameloid on the lingual face, and being markedly large in size. This is the first report of the family Echinorhinidae from the Santonian as well as the first report of the family Echinorhinidae from the Cretaceous of Japan.