Family name 西云 (Xiyun 
, 西云 ) , across the world, is a rare cognomen. The surname 西云 is characteristic of Finland, where it is a very rare surname, China, and Malaysia, where it is an extremely rare surname. In absolute terms, it is commonest in China, Finland, and the United States. Much more prevalently, 西云 is the forename as well as the last name.