Cognomen Siania (Siania 
) , around the globe, is a very rare family name. The cognomen Siania is habitual in New Zealand, where it is a rare surname, Australia, where it is a very rare surname, and the United States, where it is an extremely rare surname. Very seldom, Siania is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Siania | Australia, Mexico, United States, Brazil, New Zealand |