Sejny was formerly part of the German Empire. In the German Empire, the place was called Sejny.
The place is now called Sejny and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Sejny | Russian Empire | Sejny | 1914 |
| Sejny | Poland | Sejny | 1921 |
| Sejny | German Empire | Sudauen | 1939 |
| Sejny | Poland | Suwałki | 1945 |
| Sejny | Poland | Suwałki | 1992 |