| Name | Source | Type |
|---|---|---|
| Face Dancers | Dune universe | |
| Falleen | Star Wars | |
| Felysians | Noctis | |
| Felinus | Soldiers of the Heavens | Opportunistic Feline species that disregards all treaties and agreements |
| Fek'Ihri | Star Trek | |
| Fendahl | Doctor Who | worm-like lifeform |
| Ferengi | Star Trek | Humanoid. Diminutive stature, huge ears, civilization revolves around personal profit. Male-dominated culture, with subservient females. |
| Ferronans | Perry Rhodan | |
| Festival | Singularity Sky by Charles Stross | |
| Firebugs | Bravest Warriors | An evil race of bugs that live in the Firebug hive inside of the Lavarynth. |
| Fithp | Larry Niven's Footfall | Man-sized elephant-like aliens with multiple trunks. |
| Flat cats | Robert A. Heinlein's The Rolling Stones, compare Tribble | |
| Fleeblebroxian | Chip 'n Dale Rescue Rangers | Partially telekinetic shape-shifters |
| Floaters | X-COM: UFO Defense | |
| Flood | Halo | An extragalactic parasitic species that intends to assimilate all of existence into its hive mind. |
| Florauna | Ben 10 | Cycloptic, plant-like creatures from planet Flors Verdance who can control plants. They can generate seed bombs that unleash knockout gas or vines to trap enemies, stretch their arms far distances, generate thorns on their bodies, and merge with plant life. |
| Fludentri | Ascendancy | |
| Foamasi | Doctor Who | reptilian humanoids |
| Foralbo | Utopia | |
| Forerunner | Halo | Created Halo Rings to subdue the Flood, incredibly advanced technologically, but uncertain how far. |
| Forerunner | The History of the Galaxy (series) | |
| The Forest of Cheem | Doctor Who | plant-like humanoids |
| Formics | Ender Wiggins cycle by Orson Scott Card | A hive mind species resembling insects. They invaded Earth twice before being destroyed at their home planet by Andrew 'Ender' Wiggin. |
| Fotiallian | Star Trek | |
| Fott | Battlelords of the 23rd Century | |
| Frieza | Dragon Ball | Humanoid; Reptilian |
| Frutmaka | Ascendancy | |
| F'sherl-Ganni | Schlock Mercenary, also called 'Gatekeepers' | |
| Fulmini | Ben 10 | A race of energy beings hailing from planet Fulmas who can manipulate electricity. They invade other planets to drain their energy and sustain Fulmas. |
| Furbls | Battlelords of the 23rd Century | |
| Furling (one of the Four Great Races) | Stargate SG-1 | |
| Furon | Destroy All Humans! | Humanoid |
| Futars | Dune universe |