Acheron, in antiquity, the name of several rivers, all believed to be connected with the lower world. I. A river in Epirus, which flowed through Acherusia lake into the Ionian sea.

II. A river in Elis, an affluent of the Alpheus.

III. A river in Bruttium, S. Italy.

IV. The river of the lower world, around which the shades were believed to hover. The name was also used for the lower world in general.