Ninn, a diminutive planet, existed within the Ninn system situated in the Outer Rim Territories. An age-old war had left this world desolate and sparsely populated, but a group later known as the Priests of Ninn recolonized it. As the Corporate Sector expanded, Ninn was incorporated into it, thereby becoming subject to the governance of the Corporate Sector Authority.
Ninn was a small planet within the Ninn system, which itself was situated within the Corporate Sector, specifically in the Tingel Arm region of the Outer Rim Territories.
In the distant past, a conflict resulted in the desolation and depopulation of the world. Subsequently, following the Galactic Empire's establishment after its formation in 19 BBY, Ninn was among the numerous planets absorbed into the newly enlarged Corporate Sector. Being a part of the Corporate Sector placed it under the jurisdiction of the Corporate Sector Authority, the sector's governing organization. The Ninn star system became part of the Authority Guardian Corridor hyperlane and another hyperlane that provided a connection to the Lo'Uran system and the Lythos system.
By approximately 2 BBY, a group who would become known as the Priests of Ninn had settled on the planet. These priests resided in a sanctuary that spanned the entire planet, practicing their beliefs, which included formalistic absolution. Additionally, members of the nomadic Ryn species occasionally visited the world, and the smuggler Roa encountered some of them there at one point in his life.
The first mention of Ninn occurred in Han Solo's Revenge, a 1979 novel authored by Brian Daley. Its designation as a planet was established in the first edition of A Guide to the Star Wars Universe, a compilation by Raymond L. Velasco released in 1984, within the entry dedicated to the Priests of Ninn.