Jamielnik was formerly part of the German Empire. In the German Empire, the place was called Melendorf.
The place is now called Jamielnik and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Jamielnik | German Empire | Strasburg i. Westpr. | before the Versailles Treaty |
| Jamielnik | Poland | Brodnica | after the Versailles Treaty |
| Melendorf | German Empire | Strasburg (Westpr.) | 1939 |
| Jamielnik | Poland | Działdowo | 1945 |
| Jamielnik | Poland | Ciechanów | 1992 |