Siekowo was formerly part of the German Empire. In the German Empire, the place was called Fließen.
The place is now called Siekowo and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Siekowo | German Empire | Schmiegel | before the Versailles Treaty |
| Siekowo | Poland | Kościan | after the Versailles Treaty |
| Fließen | German Empire | Kosten (Wartheland) | 1939 |
| Siekowo | Poland | Kościan | 1945 |
| Siekowo | Poland | Leszno | 1992 |