Surname Riell (Riell 
) , in the world, is a rare last name. The surname Riell is habitual in Portugal, where it is a very rare surname, the United States, and Germany, where it is an extremely rare surname. More frequently, Riell is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Riell | Portugal, Indonesia, Philippines, United States, Democratic Republic of the Congo |
| joseph heinrich riell (b. 1725) |
|