Family name Дем'Ян (Demian 
, Дем'Ян 
, Demyan 
) , all around the world, is a common surname. The family name Дем'Ян is characteristic of Moldova, where it is quite a common surname, Romania, and Lebanon. In absolute terms, it is the most numerous in Romania, Egypt, and Nigeria. Also, Дем'Ян is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Demian | Romania, Egypt, Nigeria, United States, Argentina |
| Дем'Ян | Ukraine |
| Demyan | Romania, Egypt, Lebanon, Hungary, United States |
| Demjan | Germany, Hungary, United States, Canada, Slovakia |