Otok was formerly part of the German Empire. In the German Empire, the place was called Heimwald.
The place is now called Otok and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Otok | Russian Empire | Seradz | 1914 |
| Otok | Poland | Sieradz | 1921 |
| Otok | German Empire | Schieratz | 1939 |
| Heimwald | German Empire | Schieratz | 1939 |
| Otok | Poland | Poddębice | 1945 |
| Otok | Poland | Sieradz | 1992 |