Surname Siefener (Siefener 
) , globally, is a very rare cognomen. The last name Siefener is characteristic of Germany, where it is a very rare surname, and the United States, where it is an extremely rare surname.
| VARIANT | COUNTRY |
|---|---|
| Siefener | Germany, United States |
| michael siefener German author and translator, DE (b. 1961) |
|