Sielz (Sosnowitz-Sielz) was formerly part of the German Empire. In the German Empire, the place was called Sielz (Sosnowitz-Sielz).
The place is now called Sielec Nowy (Sosnowiec-Sielec Nowy) and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Sielec Nowy (Sosnowiec-Sielec Nowy) | Russian Empire | Bendin | 1914 |
| Sielec Nowy (Sosnowiec-Sielec Nowy) | Poland | Będzin | 1919 |
| Sielz (Sosnowitz-Sielz) | German Empire | Sosnowitz (St.Kr.) | 1939 |
| Sielec Nowy (Sosnowiec-Sielec Nowy) | Poland | Sosnowiec m. | 1945 |
| Sielec Nowy (Sosnowiec-Sielec Nowy) | Poland | Katowice | 1992 |