Aigialeia is a municipality and a former province in the eastern part of the Achaea regional unit, Greece. The seat of the municipality is the town Aigio. The municipality has an area of 723.063 km². The main towns are Aigio, Akrata and Diakopto. The municipality Aigialeia stretches from the south coast of the Gulf of Corinth to the mountainous interior of the Peloponnese peninsula. The main rivers of the municipality are the Selinountas and the Vouraikos.