Tokudaia is a genus of murine rodent native to Japan. Known as Ryūkyū spiny rats or spinous country-rats, population groups exist on several non-contiguous islands. Despite differences in name and appearance, they are the closest living relatives of the Eurasian field mouse (Apodemus).
Named species are:
- Muennink's Spiny Rat, Tokudaia muenninki
- Ryukyu Spiny Rat, Tokudaia osimensis
- Tokunoshima Spiny Rat, Tokudaia tokunoshimensis
At least Tokudaia osimensis may be a cryptic species complex.