Cognomen Gunatilak (Gunatilak 
) , in all the world, is a rare last name. The cognomen Gunatilak is habitual in Sri Lanka, where it is a rare surname, and Thailand, where it is an extremely rare surname. Much less frequently, Gunatilak is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Gunatilak | India, Sri Lanka, Thailand |