George Terter I (Bulgarian: Георги Тертер I), of the Terter dynasty ruled as emperor (tsar) of Bulgaria 1280–1292. The date of his birth is unknown, and he died in 1308/1309.
The reign of George Terter I represents a continuation of Bulgaria's precipitous decline during the second half of the 13th century. Although George Terter I managed to maintain himself on the throne for more than a decade (unlike his two immediate predecessors), he appears to have failed to assert himself against the centrifugal forces even in his own capital. This severely limited any possibility of engaging in grand-scale international politics or even standing up to foreign aggression and Mongol raids. During the chaotic years preceding George Terter I's accession Bulgaria had lost all of Thrace to the Byzantine Empire, and under his reign its remaining possessions in Macedonia were divided between the Serbians and the Byzantines in 1282–1284.