The Uesureyan Star Empire (Also known as the Uesureyan Empire or the Weslian Star Empire) was a powerful faction that succeeded the Black Claw Star Empire and preceded the Yamatai Star Empire, which slowly absorbed it. It was known for its political strength and superior technology. The Uesureyan Star Empire was a member of the United Empire Forces.

Most citizens of the Uesureyan Star Empire spoke Trade (language) and were humans, although the empire also included various alien species.

The military of the Uesureyan Star Empire was the Army Of Uesureya and the UE Spacy.

In YE 43, after Star Army of Uesureya forces appeared at the Battle Of Glimmergold, it was revealed that Kitsurugi Uesu had been attempting to revive the Uesureyan Star Empire since his exodus in YE 30 with the Uesu's Fleet.