Dioll, a planet characterized by its rocky terrain, could be found within the Dioll system situated in the Juvex sector. This sector, in turn, was a component of the Senex-Juvex area, which resided in the Western Reaches section of the Mid Rim. It is described as a planet in legends material. The Kassido Bypass hyperlane provided a connection between Dioll and both the Kardura and Thermon systems.
The atmospheric conditions on Dioll were paradoxical, as they included both powerful winds and thick fogs, thus mirroring some features of a smaller gas giant. Dioll functioned as the original homeworld for the sentient Diollan species. Similar to other planets within Senex-Juvex, Dioll was governed by the aristocratic Ancient Houses of that region.
The planet Dioll received a mention in The Essential Atlas, a reference work published in 2009. Daniel Wallace and Jason Fry were the writers of the book, and they designated its location as grid square L-17.