Sienno was formerly part of the German Empire. In the German Empire, the place was called Seefeld.
The place is now called Sienno and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Seefeld | German Empire | Weststernberg | 1939 |
| Sienno | Under Polish administration | Rzepin | 1945 |
| Sienno | Poland | Gorzów | 1992 |