Surname Onyshuk (Onyshuk 
, Онишук 
) , around the world, is a very rare cognomen. The cognomen Onyshuk is habitual in Ukraine, where it is a very rare surname, Russia, and the United States, where it is an extremely rare surname.
| VARIANT | COUNTRY |
|---|---|
| Onyshuk | United States |
| Онишук | Russia, Ukraine |