Achaia (Ἀχαΐα, Achaia). A Roman province that included most of southern and central Greece, with its capital in Corinth.

Paul was in Corinth when Gallio was deputy of Achaia (Acts 18:12). In Acts 20:2, “Greece” means Achaia, but “Macedonia and Achaia” usually refer to the whole of Greece (Acts 19:21; Rom 15:26; 1 Thess 1:8). Paul mentions the churches of Achaia because of their generosity (2 Cor 9:13).

Achaeans were the residents of the northern part of the Peloponnesian peninsula in classical Greece, and Homer refers to the Greeks as “Achaeans” in his epics. Around 280 bc, residents Achaia formed a confederation of smaller city-states called the Achaean League. In 251 bc, Aratus of Sicyon was chosen commander-in-chief. He increased the League’s power and gave it a constitution. In 146 bc, Corinth was destroyed by Rome and the League was broken up. The whole of Greece, under the name of Achaia, was transformed into a Roman province. It was divided into two separate provinces, Macedonia and Achaia, in 27 bc.