In the world, Onadia (Onadia 
) is a very rare epicene first name. The forename Onadia is characteristic of Nigeria, where it is a very rare epicene name, and Brazil, where it is an extremely rare female name. Likewise, Onadia is the last name as well as the forename.
| VARIANT | COUNTRY |
|---|---|
| Onadia | United States, Mexico, Philippines, Nigeria, Brazil |