Family name Guillia (Guillia 
) , in the world, is a very rare last name. The cognomen Guillia is habitual in Nicaragua, where it is a very rare surname, Philippines, where it is an extremely rare surname, and the United States. Measured by absolute frequency, it is commonest in Philippines, the United States, and Mexico. Predominantly, Guillia is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Guillia | Brazil, Philippines, United States, Peru, Democratic Republic of the Congo |