Aetos (Greek: Αετός meaning "eagle") is a village and a former municipality in Messenia, Peloponnese, Greece. Since the 2011 local government reform it is part of the municipality Trifylia, of which it is a municipal unit. The municipal unit has an area of 94.850 km2. In 2011 its population was 360 for the village and 1,915 for the municipal unit. The seat of the former municipality was in Kopanaki.