Sielec was formerly part of the German Empire. In the German Empire, the place was called Schielitz.
The place is now called Sielec and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Sielec-Hufen | German Empire | Znin | before the Versailles Treaty |
| Sielec | Poland | Żnin | after the Versailles Treaty |
| Schielitz | German Empire | Dietfurt (Wartheland) | 1939 |
| Sielec | Poland | Żnin | 1945 |
| Sielec | Poland | Bydgoszcz | 1992 |