Family name Ильяев (Ilyaev 
, Ильяев 
, Iliaev 
) , in all the world, is a rare last name. The last name Ильяев is habitual in Greece, where it is a rare surname, Kyrgyzstan, and Kazakhstan. Measured by absolute frequency, this name is the most popular in Russia, Kazakhstan, and Germany. Very seldom, Ильяев is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Ilyaev | Germany, China, Russia, United States, Israel |
| Ильяев | Kazakhstan, Russia, Kyrgyzstan, Belarus, Israel |
| Iliaev | Germany, Czechia, Greece, France, Israel |