Ostowo was formerly part of the German Empire. In the German Empire, the place was called Ostau, Fh..
The place is now called Ostowo and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Ostau, Fh. | German Empire | Ortelsburg | 1939 |
| Ostowo | Under Polish administration | Szczytno | 1945 |
| Ostowo | Poland | Olsztyn | 1992 |