Smolajny was formerly part of the German Empire. In the German Empire, the place was called Schmolainen.
The place is now called Smolajny and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Schmolainen | German Empire | Heilsberg | 1939 |
| Smolajny | Under Polish administration | Lidzbark Warmiński | 1945 |
| Smolajny | Poland | Olsztyn | 1992 |