Olszak Stary was formerly part of the German Empire. In the German Empire, the place was called Olszak.
The place is now called Olszak Nowy and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Olszak Stary | Russian Empire | Pultusk | 1914 |
| Olszak Nowy, Fw. | Russian Empire | Pultusk | 1914 |
| Olszak Stary | Poland | Pułtusk | 1919 |
| Olszak Nowy, Fw. | Poland | Pułtusk | 1919 |
| Olszak | German Empire | Ostenburg | 1939 |
| Olszak Stary | Poland | Pułtusk | 1945 |
| Olszak | Poland | Pułtusk | 1945 |
| Olszak Stary | Poland | Ciechanów | 1992 |
| Olszak Nowy | Poland | Ciechanów | 1992 |