Water mouse can refer to several types of not closely related semiaquatic rodents of superfamily Muroidea:
- Chibchanomys, two cricetid species from western South America;
- Las Cajas water mouse (C. orcesi)
- Chibchan water mouse (C. trichotis)
- Ethiopian water mouse or Ethiopian amphibious rat (Nilopegamys plumbeus), a murid;
- Rheomys, four cricetid species from Central America and Mexico;
- Mexican water mouse (R. mexicanus)
- Goldman's water mouse (R. raptor)
- Thomas's water mouse (R. thomasi)
- Underwood's water mouse (R. underwoodi)
- Xeromys myoides, a rodent native to Australia and Papua New Guinea