Plajny was formerly part of the German Empire. In the German Empire, the place was called Plehnen.
The place is now called Plajny and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Plehnen | German Empire | Preußisch Holland | 1939 |
| Plajny | Under Polish administration | Pasłęk | 1945 |
| Plajny | Poland | Elbląg | 1992 |