Olszak was formerly part of the German Empire. In the German Empire, the place was called Olsen.
The place is now called Olszak and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Olszak | Russian Empire | Kolo | 1914 |
| Olszak | Poland | Koło | 1921 |
| Olsen | German Empire | Warthbrücken | 1939 |
| Olszak | Poland | Koło | 1945 |
| Olszak | Poland | Konin | 1992 |