Osek was formerly part of the German Empire. In the German Empire, the place was called Osek.
The place is now called Osek and belongs to Czech Republic.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Wossek | Austro-Hungary | Strakonitz | before the Treaty of Saint-Germain |
| Vosek | Austro-Hungary | Strakonitz | before the Treaty of Saint-Germain |
| Osek | Czechoslovakia | Strakonice | after the Treaty of Saint-Germain |
| Ossek | German Empire | Strakonitz | 1939 |
| Osek | German Empire | Strakonitz | 1939 |
| Osek | Czechoslovakia | Horažďovice | 1945 |
| Osek | Czechoslovakia | Strakonice | 1992 |
| Osek | Czech Republic | Strakonice | 1993 |