Olszewnik was formerly part of the German Empire. In the German Empire, the place was called Elsau.
The place is now called Olszewnik and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Elsau | German Empire | Rößel | 1939 |
| Olszewnik | Under Polish administration | Reszel | 1945 |
| Olszewnik | Poland | Olsztyn | 1992 |