Olszewka may refer to the following places: Olszewka, Nakło County in Kuyavian-Pomeranian Voivodeship (north-central Poland) Olszewka, Ciechanów County in Masovian Voivodeship (east-central Poland) Olszewka, Ostrołęka County in Masovian Voivodeship (east-central Poland) Olszewka, Przasnysz County in Masovian Voivodeship (east-central Poland)