Last name Riua (Riua 
) , worldwide, is a very rare surname. The last name Riua is habitual in Malaysia, where it is a very rare surname, Philippines, where it is an extremely rare surname, and the United States. Very seldom, Riua is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Riua | Philippines, Malaysia, United States |