Masłowo was formerly part of the German Empire. In the German Empire, the place was called Butterfaß.
The place is now called Masłowo and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Butterfaß | German Empire | Karthaus | before the Versailles Treaty |
| Masłowo | Poland | Kartuzy | after the Versailles Treaty |
| Butterfaß | German Empire | Karthaus (Westpr.) | 1939 |
| Masłowo | Poland | Kartuzy | 1945 |
| Masłowo | Poland | Gdańsk | 1992 |