Cognomen Gaios (Gaios 
, Гайос 
, جيوس) , globally, is a very rare family name. The cognomen Gaios is habitual in Armenia, where it is a rare surname, Greece, and Georgia, where it is a very rare surname. Measured by absolute frequency, it is the most numerous in Greece, Armenia, and Nigeria. Also, Gaios is the forename as well as the last name.