Słonczewo was formerly part of the German Empire. In the German Empire, the place was called Slonczewo.
The place is now called Słonczewo and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Slonczewo | Russian Empire | Pultusk | 1914 |
| Słonczewo | Poland | Pułtusk | 1919 |
| Slonczewo | German Empire | Ostenburg | 1939 |
| Słonczewo | Poland | Pułtusk | 1945 |
| Słonczewo | Poland | Ciechanów | 1992 |