Cognomen Клиучко (Kliuchko 
, Клиучко , Klyuchko 
) , in all the world, is a rare surname. The surname Клиучко is habitual in Estonia, where it is a rare surname, Czechia, and Russia, where it is a very rare surname. Measured by absolute frequency, it most frequently occurs in Russia, Czechia, and Kazakhstan. Very seldom, Клиучко is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Kliuchko | Estonia, Israel, Russia, Ukraine |
| Клиучко | Russia |
| Klyuchko | Kazakhstan, Russia, Czechia, United States, Ukraine |