Siejkowo was formerly part of the German Empire. In the German Empire, the place was called Justusberg.
The place is now called Siejkowo and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Justusberg | German Empire | Lötzen | 1939 |
| Siejkowo | Under Polish administration | Giżycko | 1945 |
| Siejkowo | Poland | Suwałki | 1992 |