Siedlec was formerly part of the German Empire. In the German Empire, the place was called Seidlitzau.
The place is now called Siedlec and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Seidlitzau | German Empire | Landeshut i. Schles. | 1939 |
| Siedlec | Under Polish administration | Kamienna Góra | 1945 |
| Siedlec | Poland | Jelenia Góra | 1992 |