Surname Iyoku (Iyoku 
) , in the entire world, is a rare family name. The surname Iyoku is habitual in Japan, where it is a rare surname, Nigeria, where it is a very rare surname, and Brazil, where it is an extremely rare surname. Much less frequently, Iyoku is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Iyoku | Japan, Nigeria, Brazil |