The Oriolan sector was situated in the Mid Rim. By 0 ABY, it bordered the Sombure sector spinward, the Iska and Masla sectors Rimward, and the Halm sector and the Jidlor Marches in the trailing direction. The sector also formed a part of the Mid Rim's Coreward border with the Expansion Region's Har Worlds and Piryn Shar sectors.
The Oriolanis, Polomie, and Werta systems all lay within the Oriolan sector, and they contained the planet Oriolanis, the celestial body Polomie, and a terrestrial moon, respectively. The hyperlane known as the Great Gran Run passed through the northern portion of the sector, connecting it to the Halm sector's Halm system and the Har system of the Har Worlds.
As part of the Western Reaches Operation in 17 BBY, forces of the Galactic Empire traveled Rimward along the section of the Great Gran Run that passed through the Oriolan sector. During the Galactic Civil War, the Rebel Alliance maintained a stronghold on Polomie as well as a large base on the Werta system moon. At some point by 1 BBY, military forces commanded by Imperial Inspector-General Moff Rebu decimated the Rebel forces at the Polomie stronghold, and the Empire also carried out a concerted assault on the Werta system base.
Shortly before the Battle of Endor of 4 ABY, Oriolanis was the site of a shipyard that produced Imperial-class Star Destroyers for the Empire. Later that year, the forces of the extragalactic Nagai and Tof species traveled along the portion of the Great Gran Run running through the Oriolan sector while moving Coreward as part of the secondary movements of their separate invasions of the galaxy.
The Oriolan sector was established in the StarWars.com Online Companion to the 2009 reference book The Essential Atlas, which was written by Daniel Wallace and Jason Fry. In 2012, the sector was depicted on a map designed by Modi and published in the Online Companion feature "Essential Atlas Extra: Sectors of the Mid Rim."