The Geropotamos (Greek: Γεροπόταμος or Ιερός Ποταμός) is a watercourse in southern Crete in Greece.

It flows west through the Messara Plain and discharges into the Libyan Sea near Tympaki.

This river was a source of water supply for the ancient Minoan settlement of Phaistos.

[2] The Ieropotamos was heavily drawn upon by the Minoans because of the intensity of farming, even in the Bronze Age at Phaistos.

[3] Scientists have determined that the groundwater basin may have been overdrafted some time in the Bronze Age, being a contributing factor to the mysterious depopulation of Phaistos.