A new species of diogenid hermit crab, Diogenes minimus, is described and illustrated on the basis of material from shallow subtidal waters (5-19 m) in central Japan. It appears close to D. holthuisi Asakura Tachikawa, 2010, but easily distinguished from the latter by the shape of the antennal acicle, non-elongate male left cheliped and the armature of the right cheliped merus. Including the new species, 14 identified species of Diogenes are now known from Japanese waters. A brief overview on species of Diogenes recorded from Japanese waters is given.
Keywords: Decapoda, Boso Peninsula, Diogenes minimus, Izu Peninsula, shallow subtidal.