Ostra was formerly part of the German Empire. In the German Empire, the place was called Ostrá.
The place is now called Ostrá and belongs to Czechoslovakia.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Ostra | Austro-Hungary | Jungbunzlau | before the Treaty of Saint-Germain |
| Ostrá | Austro-Hungary | Jungbunzlau | before the Treaty of Saint-Germain |
| Ostrá | Czechoslovakia | Mladá Boleslav | after the Treaty of Saint-Germain |
| Ostra | German Empire | Jungbunzlau | 1939 |
| Ostrá | German Empire | Jungbunzlau | 1939 |
| Ostrá | Czechoslovakia | Mladá Boleslav | 1945 |
| Ostrá | Czechoslovakia | Střední Čechy | 1992 |