Surname Siilak (Siilak 
) , throughout the world, is a rare family name. The cognomen Siilak is characteristic of Northern Europe, particularly Estonia, where it is quite a common surname.
| VARIANT | COUNTRY |
|---|---|
| Siilak | Estonia |
|
marko siilak EE (b. 1980) |
|
| jaan siilak Estonian rower, EE (b. 1942) |
|