The Cygnus Star Empire was an interplanetary state that straddled the Oktos Route in the Mid Rim and lay immediately coreward of Hutt Space.
The Star Empire was located on the Oktos Route in the Mid Rim. The region consisted of a handful of systems a few parsecs wide. Due to its closeness to Hutt Space, just coreward of the region, it was believed to have originally been a bribe offered to several of Xim's allies by the Hutt warlord Kossak during the Xim Wars.
The Cygnus Spaceworks ship manufacturers were headquartered within the empire's domain and the region was known to use Tionese lettering, much like the Cluster itself.
The Cygnus Star Empire apparently originates in the fan-made work Book of Imperial Shuttle Plans: Cygnus Spaceworks, published almost two decades before the name was referenced in canon material. In Imperial Shuttle Plans, the Cygnus Star Empire was associated with "Cygnus Spaceworks" and a "Cygnus system." The Spaceworks was later referenced in canon, in the Star Wars Technical Journal and the video game Star Wars: TIE Fighter.