Apollonia is an inhabited planet located in the Alpha Sigma star system, at coordinates 4.44N 6.37E.

In the 23rd century, Apollonia was home to an Federation colony with a civilization based on agriculture and industry. In the late 23rd century, the world had a population of 1.38 billion individuals of mixed and varied racial origins, and the government was a colonial member of the Federation. (FASA RPG module: The Federation)

It was not specified what this world's location was in the Alpha Sigma star system, but it is possible this is the same planet as Alpha Sigma IX.