Technically speaking, the first Orion to appear in Star Trek was Marta in Whom Gods Destroy. Vina, as "Orion slave girl" was a Talosian illusion in The Cage, and doubly so in The Menagerie, Part II.

A group of aliens who used members of their own race to entice others. In the original series, they became known as the "Orion slave girls". In Star Trek: Enterprise, it was shown that the Orion ...