Sińczyk was formerly part of the German Empire. In the German Empire, the place was called Blaustein, Klein.
The place is now called Sińczyk and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Blaustein, Klein | German Empire | Rastenburg | 1939 |
| Sińczyk | Under Polish administration | Kętrzyn | 1945 |
| Sińczyk | Poland | Olsztyn | 1992 |