Thesalla was a planet located somewhere in the space of the galaxy's Alpha or Beta Quadrants, in orbit of the Tharsis star system, at coordinates 5.26N 3.46W.

In the 23rd century, Thesalla was home to a Andorian mining colony, a noted cultural center. By reference stardate 2/2306.01, the world had a population of 3.16 billion individuals, mostly Andorian, and the government was a full-status colonial member of the Federation. (FASA RPG module: The Federation)