Osjakow was formerly part of the German Empire. In the German Empire, the place was called Ostwerder.
The place is now called Osjaków and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Osjakow | Russian Empire | Veljunˈ | 1914 |
| Osjaków | Poland | Wieluń | 1921 |
| Osjaków | German Empire | Welungen | 1939 |
| Ostwerder | German Empire | Welungen | 1939 |
| Osjaków | Poland | Wieluń | 1945 |
| Osjaków | Poland | Sieradz | 1992 |