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