Acamantis () was one of the phylai (tribes) of classical Athens, created during the reforms of Cleisthenes. It was named after the legendary hero Acamas, and included the demes of Cholargos, Eiresidai, Eitea, Hagnous, Hermos, Iphistiadai, Kephale, Kerameis, Kikynna, Kyrteidai, Poros, Prospalta, Sphettos and Thorikos.