U
- Uma inornata — Coachella Valley Fringe-toed Lizard
- Uncia uncia — Ounce, Snow Leopard
- Urocyon littoralis — California Channel Island Fox, Channel Islands Fox, Island Fox, Island Gray Fox
- Urogymnus ukpam — Pincushion ray
- Urolophus javanicus — Java stingaree
- Urolophus orarius — Coastal stingaree
- Uromys rex — King Rat
- Uropsilus investigator — Inquisitive Shrew Mole
- Uropsilus soricipes — Chinese Shrew Mole
- Urothemis thomasi
Read more about this topic: IUCN Red List Endangered Animal Species