Surname Сергиичук (Сергиичук 
, Sergiichuk 
) , in all the world, is a very rare last name. The cognomen Сергиичук is habitual in Greece, where it is a very rare surname, Russia, and Ukraine, where it is an extremely rare surname.
| VARIANT | COUNTRY |
|---|---|
| Сергиичук | Russia |
| Sergiichuk | Ukraine, Russia, Greece, United States |