Zahájí was formerly part of the German Empire. In the German Empire, the place was called Zahájí.
The place is now called Zahájí and belongs to Czech Republic.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Zahaj | Austro-Hungary | Melnik | before the Treaty of Saint-Germain |
| Zaháj | Austro-Hungary | Melnik | before the Treaty of Saint-Germain |
| Zahájí | Czechoslovakia | Mělník | after the Treaty of Saint-Germain |
| Sahaj | German Empire | Melnik | 1939 |
| Zahájí | German Empire | Melnik | 1939 |
| Zahájí | Czechoslovakia | Mělník | 1945 |
| Zahájí | Czechoslovakia | Mělník | 1992 |
| Zahájí | Czech Republic | Mělník | 1993 |