The Thyamis (Greek: Θύαμις), also known as Glykys (Γλυκύς)[1] or Kalamas (Καλαμάς),[2][3] is a river in the Epirus region of Greece.

It receives its tributary Tyria near Vrosina, and turns west near Kyparisso in Thesprotia, where the hydroelectric dam is located.

It empties into the Ionian Sea near the village Kestrini, between Igoumenitsa and Sagiada, close to the Albanian border.

Places along the river include, from source to mouth: Mazaraki, Soulopoulo, Vrosina, Raveni, Pente Ekklisies, Kyparisso, Parapotamos and Kestrini.

The river, however, has suffered from environmental degradation for decades, due to uncontrolled human activities (farming activity, urban and industrial effluents and waste, lack of management plan and poor coordination of competent authorities for its protection).