Cognomen Ruca (Ruka 
, Ruca 
, Rauke 
) , worldwide, is a common surname. The cognomen Ruca is characteristic of Albania, where it is quite a common surname, Latvia, where it is quite a rare surname, and Nigeria. Not in comparison with a country's population, it is the most numerous in Nigeria, India, and Indonesia. Likewise, Ruca is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Ruka | Nigeria, Indonesia, South Africa, Albania, India |
| Ruca | Angola, South Africa, United States, Poland, India |
| Rauke | Germany, China, United States, South Africa, India |
| Eruca | India, United States |