Cognomen Tsas (สาส 
, Tsas 
) , in all the world, is a very rare surname. The surname Tsas is characteristic of Belgium, where it is a rare surname, Netherlands, where it is a very rare surname, and Australia. Not in comparison with a country's population, it is the most numerous in Belgium, the United States, and Spain. Much less frequently, Tsas is the forename as well as the last name.