Cognomen Posan (Posan 
, โปษัณ 
) , worldwide, is a rare surname. The surname Posan is characteristic of Hungary, where it is quite a rare surname, Romania, where it is a rare surname, and Canada, where it is a very rare surname. Not in comparison with a country's population, it is commonest in Hungary, India, and Indonesia. More prevalently, Posan is the forename as well as the last name.