Acarnania was a region of ancient central western Greece that lay along the Ionian Sea, west of Aetolia, with the Achelous River for a boundary, and north of the gulf of Calydon, which is the entrance to the Gulf of Corinth. The capital and principal city was Stratos .

Acarnania's foundation was ascribed to Acarnan, son of Alcmaeon; its population was addicted to piracy.

When the Byzantine Empire broke up (1204), Acarnania passed to the Despotate of Epirus and in 1480 to the Ottoman Turks. Since 1832 it has been part of Greece.