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 | Nigeria, United States, Egypt, Argentina, Romania |
| Дем'Ян | Ukraine |
| Demyan | Hungary, United States, Egypt, Lebanon, Romania |
| Demjan | Hungary, Germany, Canada, United States, Slovakia |