Ylesia was a planet of the terrestrial type, situated in the Outer Rim Territories segment of Hutt Space. This planet, together with its satellite, the Codian Moon, functioned as the original homeworld for the reek species. It could be found in the Hutt Space area of the galaxy's Outer Rim Territories, connected to both Teth and Rorak via established hyperspace routes. Maz Kanata, the one-time pirate queen, identified it as a location of significance on a navigational chart she placed within the book that came to be known as Smuggler's Guide.
Within established canon, Ylesia's initial mention occurred in the 2015 re-release of the book for young readers, Journey Through Space, authored by Ryder Windham. The planet's origins lie in the Star Wars Legends timeline, making its debut in The Paradise Snare, a 1997 novel penned by A. C. Crispin.