Thermo (Greek: Θέρμο, before 1915: Κεφαλόβρυσον Kefalovryson)[2] is a town and a municipality in Aetolia-Acarnania, Greece.

It is located in the southeastern part of the regional unit, largely between Lake Trichonida (the largest natural lake in Greece) and the southern border of Evrytania.

It has a land area of 333.701 km2 (129 sq mi)[3] and a population of 5,712 inhabitants (2021 census).

The village of Megas Dendros (part of the community of Thermo) was the birthplace of Cosmas of Aetolia.

The municipality Thermo consists of the following communities: This Western Greece location article is a stub.