Eothyris is an extinct genus of synapsids in the family Eothyrididae from the Permian. It was an insectivorous animal, closely related to Oedaleops. Only the skull of Eothyris, first described in 1937, is known. It had a 6-centimetre-long (2.4-inch) skull, and its total estimated length is 30 centimetres (12 inches).