Nowy Gaj was formerly part of the German Empire. In the German Empire, the place was called Gärtringen.
The place is now called Nowy Gaj and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Gay | German Empire | Osterode i. Ostpr. | 1938 |
| Gärtringen | German Empire | Osterode i. Ostpr. | 1939 |
| Nowy Gaj | Under Polish administration | Ostróda | 1945 |
| Nowy Gaj | Poland | Olsztyn | 1992 |