George Choumnos was a younger son of the scholar and statesman Nikephoros Choumnos, and brother of the general and statesman John Choumnos. According to Rodolphe Guilland, he is possibly to be identified with the otherwise unknown "megas stratopedarches" Choumnos, attested in 1328. At that time, during the final stages of the Byzantine civil war of 1321–1328, he was the governor of Thessalonica and defended the city unsuccessfully against the forces of Andronikos III Palaiologos. He appears again in the late reign of Andronikos III, from 1337 on, holding the position of "epi tes trapezes" (head of the imperial table). He was evidently an influential person: his unnamed son had family ties to Andronikos III, and George himself is attested as speaking first in imperial councils, even before Andronikos III's close friend and aide, the "megas domestikos" John Kantakouzenos. In 1339, he is also attested as head ("kephalatikeuon") of one of the districts of Constantinople.