Family name Demiankov (Демьянков 
, Демянков 
, Demiankov ) , around the world, is a rare cognomen. The surname Demiankov is habitual in Belarus, where it is quite a rare surname, Russia, where it is a rare surname, and Kazakhstan, where it is a very rare surname. Not in comparison with a country's population, it is commonest in Eastern Europe, particularly Russia, Belarus, and Ukraine. Much less frequently, Demiankov is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Демьянков | Belarus, Russia, Kazakhstan |
| Демянков | Belarus, Russia, Kazakhstan, Ukraine |
| Demiankov | Ukraine, Russia |