Cognomen Tiyun (体云 
, Tiyun 
) , in the entire world, is a very rare surname. The family name Tiyun is habitual in Malaysia, where it is a very rare surname, China, where it is an extremely rare surname, and Thailand. Not in comparison with a country's population, it is the most numerous in China, Malaysia, and India. More frequently, Tiyun is the forename as well as the last name.