Jels Trolkjer was formerly part of the German Empire. In the German Empire, the place was called Jels Trolkjer.
The place is now called Jels Troldkær and belongs to Denmark.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Jels Trolkjer | German Empire | Hadersleben | before the Versailles Treaty |
| Jels-Troldkær | Denmark | Haderslev | after the Versailles Treaty |
| Jels Troldkær | Denmark | Sønderjylland | 1993 |