Peaceful, advanced humanoids of Zeon who were persecuted by an Ekosian regime modelled on Nazi Germany by the historian John Gill.
The Zeons are a peaceful and technologically advanced humanoid people from Zeon, one of two inhabited planets in the M43 Alpha system along with Ekos. Before the events of their key episode, many Zeons lived on Ekos itself.
In Patterns of Force, Kirk and Spock discovered that the Federation historian John Gill had reshaped Ekosian society on the model of Nazi Germany. The regime persecuted the Zeons living on Ekos and prepared to invade their homeworld. Working with the Zeon underground, including Isak, Kirk and Spock exposed the deception and brought the regime down.