Łacnów was formerly part of the German Empire. In the German Empire, the place was called Latzenowe.
The place is now called Łacnów and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Lacenowe | German Empire | Groß-Wartenberg | before the Versailles Treaty |
| Łacnów | Poland | Ostrów Wielkopolski | after the Versailles Treaty |
| Latzenowe | German Empire | Ostrowo | 1939 |
| Łacnów | Poland | Ostrów Wielkopolski | 1945 |
| Łacnów | Poland | Kalisz | 1992 |