|Bodies:||At least 2|
|Affiliation:||Unified Earth Government|
According to Halo: Contact Harvest, the system had not been involved in the Insurrection as of 2524; its stability is stated to be in part due to the uniform ethnic and religious makeup of the population. However, in Halo 4: Forward Unto Dawn, Cygnus is described as having been embroiled in the Insurrection for years as of 2526.
 List of appearances
- Halo: Contact Harvest (First appearance)
- Halo: Reach (Mentioned only)
- Halo 4: Forward Unto Dawn (Mentioned only)