thumb|Demeter on the Agelasta stone relief, [[Archaeological Museum of Eleusis, Greece.]]
In Greek mythology, Agelasta (, , "smile-less stone") was the name of the stone on which Demeter rested during her search for Persephone.
In modern culture, Agelasta inspired the title of a documentary by Philippos Koutsaftis (Φίλιππος Κουτσαφτής), called Agelastos Petra (Αγέλαστος Πέτρα, "smile-less stone", 2000).