Dereium or Dereion (Greek, Ancient (to 1453);: Δέρειον), also known as Dera (Δέρα) and Derrhium or Derrhion (Δέρριον),[1] was a town of ancient Laconia. Pausanias writes that it was on Taygetus not far from Lapithaeum, and 20 stadia from Harpleia. Dereium possessed an open image of Artemis Dereatis, and a spring called Anonus.
Its site is unlocated.