Family name Oniell (Oniell 
) , globally, is a rare cognomen. The family name Oniell is characteristic of Jamaica, where it is a rare surname, Nicaragua, and the United Kingdom, where it is a very rare surname. Not in comparison with a country's population, it is the most numerous in the United States, the United Kingdom, and Jamaica. Much less frequently, Oniell is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Oniell | Australia, Jamaica, Canada, United States, United Kingdom |