Family name Aventajado-Sia (Aventajado-Sia 
) , throughout the world, is an extremely rare last name. The family name Aventajado-Sia is habitual in South-eastern Asia, particularly Philippines, where it is an extremely rare surname. Parts of the name also exists independently as a last name Aventajado, and a last name Sia.
| VARIANT | COUNTRY |
|---|---|
| Aventajado-Sia | Philippines |