Last name Semjanov (Семянов 
, Semjanov 
) , around the globe, is a rare cognomen. The family name Semjanov is characteristic of Serbia, where it is quite a rare surname, Australia, where it is a very rare surname, and Russia. Not in comparison with a country's population, it is the most numerous in Serbia, Russia, and Ukraine. Much less frequently, Semjanov is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Семянов | Ukraine, Kyrgyzstan, Kazakhstan, Russia |
| Semjanov | Australia, Canada, Serbia |