Fish-eating rat can refer to several related semiaquatic South American rodents of tribe Ichthyomyini:
- Anotomys, one species:
- Ecuador fish-eating rat, fish-eating rat or aquatic rat (A. leander)
- Neusticomys, six species:
- Ferreira's fish-eating rat (N. ferreirai)
- Montane fish-eating rat (N. monticolus)
- Musso's fish-eating rat (N. mussoi)
- Oyapock's fish-eating rat (N. oyapocki)
- Peruvian fish-eating rat (N. peruviensis)
- Venezuelan fish-eating rat (N. venezuelae)