Elas was an inhabited planet, the outer of the two, the other being Troyius, found within the Tellun star system in the Alpha Quadrant. This was the homeworld of the Elasians, a spacefaring humanoid species. This system was located in a border area near the Federation-Klingon border.
In 2256, this planet was mentioned with the star system's name on the star chart "Alpha/Beta Quadrant Overview" in the ready room aboard the USS Discovery. (DIS: "Magic to Make the Sanest Man Go Mad")
The planet had rich deposits of dilithium ("radan" in the Troyian language). In 2268, both planets possessed the capability of mutual destruction. The wedding of the Dohlman of Elas, Elaan, to the ruler of Troyius preserved the peace. (TOS: "Elaan of Troyius")