The Thyamis (Greek: Θύαμις), also known as Glykys (Γλυκύς) or Kalamas (Καλαμάς), is a river in the Epirus region of Greece. It flows into the Ionian Sea. The names of the Chameria region (Tsiamouria in Greek), as well as the former Cham minority, derive from the river's name.