Surname Demyanchuk (Демянчук 
, Демьянчук 
, Demyanchuk 
) , throughout the world, is quite a rare cognomen. The cognomen Demyanchuk is characteristic of Eastern Europe, particularly Belarus, where it is quite a rare surname, Ukraine, and Russia.
| VARIANT | COUNTRY |
|---|---|
| Демянчук | Kazakhstan, Ukraine, Belarus, Russia |
| Демьянчук | Kazakhstan, Russia, Georgia, Belarus, Ukraine |
| Demyanchuk | Russia, Spain, Bulgaria, United States, Ukraine |
| Демианчук | Russia |
Mr, Maksym, Mykola, Sergiy, Sergey, Serhiy, Stepan, Alexey, Alyona, Andrei, Andrey, Andriy, Bohdan, Darina, Dmitry, Nadiya, Oksana, Yuliya, Larissa, Tetyana, Vitaliy, Svetlana, Mariya, Yuriy, Olena, Iryna, Ms, Maya, Anna, Dima, Gali, Inna, Ivan, Igor, Olga, Alina, Svitlana, Anton, Pavlo, Raisa, Roman, Julie, Tanya, Taras, Elena, Vasyl, Venka, Irina, Pavel, and Anatoliy