Antarctica has no official flag as it is not a nation nor is it ruled by a single government or body. The Antarctic Treaty Organization adopted a flag in 2002 and is used as an unofficial symbol of the continent. Also, several unofficial designs have been proposed.

The consultative members of the Antarctic Treaty System officially adopted an emblem in 2002 which is sometimes used in the form of a flag. Officially this emblem represents the Antarctic Treaty System and not the continent itself. Antarctic Treaty members used the emblem for at least 30 years prior to its formal adoption, having used it on a 1971 commemorative stamp. Wikipedia