Olza was formerly part of the German Empire. In the German Empire, the place was called Olsau.
The place is now called Olza and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Olsau | German Empire | Ratibor | before the Versailles Treaty |
| Olza | Poland | Rybnik | after the Versailles Treaty |
| Olsau | German Empire | Ratibor (mit Hultschiner Land) | 1939 |
| Olza | Poland | Rybnik | 1945 |
| Olza | Poland | Katowice | 1992 |