Surname Янйун (Yanyun 
, Янйун 
, Janjun 
) , around the world, is a rare cognomen. The last name Янйун is habitual in Thailand, where it is a very rare surname, Spain, and Malaysia, where it is an extremely rare surname. In absolute terms, it most frequently occurs in China, Thailand, and Spain. Much more frequently, Янйун is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Yanyun | United States, Taiwan, Singapore, China, France |
| Янйун | Russia |
| Janjun | Thailand, Switzerland, Canada, United States, Philippines |