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