Kierzek was formerly part of the German Empire. In the German Empire, the place was called Kierzek.
The place is now called Kierzek and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Kierzek | Russian Empire | Ostrolenka | 1914 |
| Kierzek | Poland | Ostrołęka | 1919 |
| Kierzek | German Empire | Scharfenwiese | 1939 |
| Kierzek | Poland | Ostrołęka | 1945 |
| Kierzek | Poland | Ostrołęka | 1992 |