Arymbas (or Arybas, Arybbas) was the king of Epirus, succeeding his brother Neoptolemos in the year 360 BC. Both Arymbas and Neoptolemos claimed to be descendants of another Neoptolemos, the son of Achilles. Arymbas was the father of Aeacides of Epirus by Troas and the son of Alcetas II of Epirus.

Arymbas made a treaty of alliance with Philip of Macedon, which was cemented by a marriage between Philip and Neoptolemos' daughter, Olympias. Olympias later became known as the mother of Alexander the Great.

Pausanias 1.11

This Pyrrhus was not related to Alexander, except by ancestry. Pyrrhus was son of Aeacides, son of Arybbas, but Alexander was son of Olympias, daughter of Neoptolemus, and the father of Neoptolemus and Aryblas was Alcetas, son of Tharypus. And from Tharypus to Pyrrhus, son of Achilles, are fifteen generations