Olszyny [ɔlˈʂɨnɨ] is a village in the administrative district of Gmina Myszyniec, within Ostrołęka County, Masovian Voivodeship, in east-central Poland. It lies approximately 9 kilometres (6 mi) south-west of Myszyniec, 33 km (21 mi) north-west of Ostrołęka, and 124 km (77 mi) north of Warsaw.