List of fictional alien species: U
| Name | Source | Type |
|---|---|---|
| Ul-Mor | Star Frontiers | Nomadic land octopuses |
Umgah |
Star Control | |
Unas |
Stargate SG-1 | |
| Uncle of the Ramen Shop | Taro the Space Alien | an alien who cooks ramen has three daughters |
Uncreated |
Marvel Comics | |
Unggoy |
Halo |
|
| Ungooma | Ascendancy |
|
| Uniocs | Schlock Mercenary | |
Unity |
Superman: The Animated Series | |
Ur-Quan Kohr-Ah |
Star Control | |
Ur-Quan Kzer-Za |
Star Control | |
| Urpneys | The Dreamstone | |
| U'tani | Star Trek | |
| Utrom | Teenage Mutant Ninja Turtles | |
Utwig |
Star Control | Humanoid |
| Uxorite | Ben 10 |