Olszewo was formerly part of the German Empire. In the German Empire, the place was called Erlenau.
The place is now called Olszewo and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Olschewen | German Empire | Sensburg | 1938 |
| Erlenau | German Empire | Sensburg | 1939 |
| Olszewo | Under Polish administration | Mrągowo | 1945 |
| Olszewo | Poland | Suwałki | 1992 |