Mladějov was formerly part of the German Empire. In the German Empire, the place was called Mladějov.
The place is now called Mladějov and belongs to Czechoslovakia.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Mladějow | Austro-Hungary | Jitschin | before the Treaty of Saint-Germain |
| Mladějov | Austro-Hungary | Jitschin | before the Treaty of Saint-Germain |
| Mladějov | Czechoslovakia | Jičín | after the Treaty of Saint-Germain |
| Mladejow | German Empire | Jitschin | 1939 |
| Mladějov | German Empire | Jitschin | 1939 |
| Mladějov | Czechoslovakia | Jičín | 1945 |
| Mladějov | Czechoslovakia | Východní Čechy | 1992 |