| Name | Source | Type | |
|---|---|---|---|
| Ul-Mor | Star Frontiers | Nomadic land octopuses | |
| Star Control | |||
| Stargate SG-1 | |||
| Uncle of the Ramen Shop | Taro the Space Alien | an alien who cooks ramen has three daughters | |
| Halo | |||
| Ungooma | Ascendancy | ||
| Uniocs | Schlock Mercenary | ||
| Star Control | |||
| Star Control | |||
| Urpneys | The Dreamstone | ||
| Star Trek | |||
| Utrom | Teenage Mutant Ninja Turtles | ||
| Star Control | Humanoid | ||
| Uxorite | Ben 10 |