Olszewko was formerly part of the German Empire. In the German Empire, the place was called Elswalde.
The place is now abandoned and the area belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Olszewko | German Empire | Bromberg | before the Versailles Treaty |
| Olszewko | Poland | Bydgoszcz | after the Versailles Treaty |
| Elswalde | German Empire | Bromberg | 1939 |
| Olszewko | Poland | Bydgoszcz | 1945 |
| - aufgelassen - | Poland | Bydgoszcz | 1992 |