Sedletz was formerly part of the German Empire. In the German Empire, the place was called Sedlec.
The place is now called Sedlec and belongs to Czechoslovakia.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Sedletz | Austro-Hungary | Jungbunzlau | before the Treaty of Saint-Germain |
| Sedlec | Austro-Hungary | Jungbunzlau | before the Treaty of Saint-Germain |
| Sedlec | Czechoslovakia | Mladá Boleslav | after the Treaty of Saint-Germain |
| Sedletz | German Empire | Jungbunzlau | 1939 |
| Sedlec | German Empire | Jungbunzlau | 1939 |
| Sedlec | Czechoslovakia | Mladá Boleslav | 1945 |
| Sedlec | Czechoslovakia | Střední Čechy | 1992 |