Aigio (Greek: Αίγιο, Latin: Aegium) is a town and a former municipality in Achaea, West Greece, Greece. Since the 2011 local government reform it is part of the municipality Aigialeia, of which it is the seat and a municipal unit. Its population is around 30,000. Aigio is surrounded by trees in the north and cliffs in the northwest. The city can be accessed by GR-8A from the south and west. Mountains neighbor the southern part. The commune was known as Vostitsa or Vostizza from the Middle Ages until the 20th century and in medieval French Vostice.