Family name 希云 (Xiyun 
, 希云 ) , all over the world, is a rare last name. The family name 希云 is habitual in Finland, where it is a very rare surname, China, and Malaysia, where it is an extremely rare surname. Measured by absolute frequency, this name is the most popular in China, Finland, and the United States. Much more frequently, 希云 is the forename as well as the last name.