| PLANET | |
| Arachnia | |
 Queen Arachnia on Arachnia | |
| Affiliation: | Arachnia Empire |
| Location: | Alpha Quadrant |
| Dominant Species: | Spider People |
| Warp Capable: | yes |
| Population: | 9.85 trillion |
| Capital: | Arachnia city |
| Length of day: | 24 hours |
Arachnia was a fictional location. While participating in Tom Paris' holodeck program The Adventures of Captain Proton, Captain Kathryn Janeway (impersonating Queen Arachnia) claimed that "It's lonely at the top" was a saying originating from Arachnia.
In the dark mirror universe, the planet Arachnia was the real homeworld of the Spider People and that "It's lonely at the top" was a saying originating from Arachnia.