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