The flag of Macedonia (Greek: Σημαία της Μακεδονίας) represents a Vergina Sun with 16 rays extending from the blue field. The Vergina Sun on a blue background is commonly used as an unofficial flag of the three peripheries, the prefectures and the municipalities of Macedonia. It is also used by organisations of the Macedonian Greek diaspora, such as the Pan-Macedonian Associations of the United States and Australia, as well as numerous commercial enterprises.
Although the Vergina Sun is an official state emblem of Greece, no such provisions have been made for the flag of Macedonia, which remains unofficial.
It is unclear when the flag was adopted, but it was most likely in use by the late 1980s after the archaeological discovery of the star by Manolis Andronikos in Vergina. The similarity of the first flag of the Republic of Macedonia in 1992 after it seceded from Yugoslavia, which had the same design but on a red background with proportions 1:2, caused controversy in Greece, which was already using that symbol for its own province of Macedonia, and the Republic of Macedonia changed its flag to the current design.