George Megas Komnenos (Greek: Γεώργιος Μέγας Κομνηνός, Geōrgios Mégas Komnēnos; c. 1255 – after 1284) was Emperor of Trebizond from 1266 to 1280. He was the elder son of Emperor Manuel I and his third wife, Irene Syrikaina, a Trapezuntine noblewoman. He succeeded his half-brother Andronikos in 1266 and ruled for 14 years. George was the first Trapezuntine emperor to officially use the style Megas Komnenos ("grand Komnenos"), which had previously been merely a nickname.
The House of Komnenos (pl. Komnenoi; Greek: Κομνηνός, pl. Κομνηνοί, pronounced [komniˈni]), Latinized as Comnenus (pl. Comneni), was a Byzantine Greek noble family who ruled the Byzantine Empire in the 11th and 12th centuries. The first reigning member, Isaac I Komnenos, ruled from 1057 to 1059. The family returned to power under Alexios I Komnenos in 1081 who established their rule for the following 104 years until it ended with Andronikos I Komnenos in 1185. In the 13th century, they founded the Empire of Trebizond, a Byzantine rump state which they ruled from 1204 to 1461. At that time, they were commonly referred to as Grand Komnenoi (Μεγαλοκομνηνοί, Megalokomnenoi), a style that was officially adopted and used by George Komnenos and his successors. Through intermarriages with other noble families, notably the Doukas, Angelos, and Palaiologos, the Komnenos name appears among most of the major noble houses of the late Byzantine world.