Cognomen Сиделник (Sidelnik 
, Сиделник , Sydelnyk) , worldwide, is a rare family name. The surname Сиделник is characteristic of Israel, where it is a rare surname, Poland, and Argentina, where it is a very rare surname. In absolute terms, it is commonest in Poland, Russia, and the United States. Likewise, Сиделник is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Sidelnik | Russia, United States, Poland, Argentina, Israel |
| Сиделник | Russia |