Aitoliko is a town and a former municipality in Aetolia-Acarnania, West Greece, Greece. Since the 2011 local government reform, it is part of the municipality Messolonghi, of which it is a municipal unit. The municipal unit has an area of 129,305 m2. It is located north of the Acheloos delta. The Greek National Road 5/E55 passes through the municipal unit. It is located SW of Agrinion, about 20 km NW of Messolonghi, W of Nafpaktos and the Rio-Antirrio bridge and SE of Astakos.