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