Aroania (Greek: Αροάνια), also known as Helmos or Chelmos (Χελμός, from South Slavic chlmo, "summit"[3]), is a mountain in Achaea, Peloponnese, Greece.

The slightly higher Kyllini mountain is about 15 km to its east, separated from Aroania by the valley of the river Olvios.

The rivers Krios, Krathis and Vouraikos drain the mountain towards the Gulf of Corinth in the north.

The river Aroanios drains the mountain towards the southwest, to the Ionian Sea.

Aroania is rich in butterfly species,[4] including the Chelmos blue (Agrodiaetus iphigenia) which is found between 1,100 m and 1,800 m.[5]