Family name Demergis (Demergis 
) , in the entire world, is a very rare cognomen. The cognomen Demergis is habitual in Belarus, where it is a very rare surname, and the United States, where it is an extremely rare surname. Very seldom, Demergis is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Demergis | Belarus, United States |