Monounios or Monunius (Ancient Greek: Μονούνιος; Latin: Monunius; ruled c. 290 – 270 BC) was an Illyrian king who reigned in southern Illyria, in the territory of the Taulantii, around the hinterland of Dyrrhachion and Apollonia. He is the first known Illyrian king to have struck his own silver coins, which were minted in Dyrrhachion. The fact that Monounios' coins were struck in the city mint of Dyrrhachion stresses that he exercised to some extent his authority over the city, as did his successor and probably son Mytilos later.
Monounios is considered the successor of Glaucias of Taulantii, and probably his son. His realm also included the southern part of the later kingdom of Agron and Teuta. Monounios must have been a powerful Illyrian king who conceivably increased his dominion during the period when Pyrrhus of Epirus was in Italy. Monounios was involved in the dynastic struggles in Macedon, waging war as an ally of Lysimachus' son, Ptolemy Epigonos, against Ptolemy Ceraunos, most likely from spring 280 BC until at least the early 279 BC. A helmet with the inscribed name of the king was found around Lake Ohrid.