Orion slave girls have been with Star Trek since, literally, the beginning of Trek. (This image is Vina, as slave girl, in The Cage.)
Okay, I know -- they're from Orion. But Orion is a constellation. And, while it's likely that in the original pilot, the name was used because it was recognizable, was the location discussed later in the series?
Was it a name used by non-native species because they were from a star within the constellation? Or are they not even from anywhere related to the constellation?