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