Gnojnik was formerly part of the German Empire. In the German Empire, the place was called Hnojnik.
The place is now called Hnojník and belongs to Czech Republic.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Hnojnik | Austro-Hungary | Teschen/Cieszyn,Český Těšín | before the Treaty of Saint-Germain |
| Gnojnik | Austro-Hungary | Teschen/Cieszyn,Český Těšín | before the Treaty of Saint-Germain |
| Hnojník | Austro-Hungary | Teschen/Cieszyn,Český Těšín | before the Treaty of Saint-Germain |
| Hnojník | Czechoslovakia | Český Těšín | after the Treaty of Saint-Germain |
| Gnojnik | Czechoslovakia | Český Těšín | after the Treaty of Saint-Germain |
| Gnojnik | Poland | Cieszyn/Český Těšín | 1938 |
| Hnojnik | German Empire | Teschen | 1939 |
| Hnojník | Czechoslovakia | Český Těšín | 1945 |
| Hnojník | Czechoslovakia | Frýdek-Místek | 1992 |
| Hnojník | Czech Republic | Frýdek-Místek | 1993 |