Cognomen Seiku (سيكو 
, Seiku 
, Сейку 
) , throughout the world, is quite a rare family name. The cognomen Seiku is characteristic of Egypt, where it is quite a rare surname, Sudan, and Iraq. Likewise, Seiku is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| سيكو | Saudi Arabia, Sudan, Algeria, Egypt, Iraq |
| Seiku | Japan, Malaysia, Australia, Nigeria, India |
| Сейку | Russia |