Callium or Kallion (), or Callipolis or Kallipolis (Καλλίπολις), was the chief town of the Callienses (οἱ Καλλιῆς), situated on the eastern confines of ancient Aetolia, on one of the heights of Mount Oeta, and on the road from the valley of the Spercheus to Aetolia. It was by this road that the Gauls marched into Aetolia in 279 BCE, when they surprised and destroyed Callium, and committed the most horrible atrocities on the inhabitants. Calliumn also lay on the road from Pyra (the summit of Oeta, where Heracles was supposed to have burnt himself) to Naupactus, and it was divided by Mount Corax from lower Aetolia.