Surname Задоян (Задоян 
, Zadoyan 
) , all around the world, is a rare family name. The family name Задоян is characteristic of Armenia, where it is quite a rare surname, Ukraine, where it is a rare surname, and Russia. Also, Задоян is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Задоян | Russia, Armenia, Kazakhstan, Ukraine |
| Zadoyan | Armenia, Canada, United States, Germany, Russia |