Seroczyn [sɛˈrɔt͡ʂɨn] is a village in the administrative district of Gmina Czerwin, within Ostrołęka County, Masovian Voivodeship, in east-central Poland. It lies approximately 6 kilometres (4 mi) east of Czerwin, 24 km (15 mi) south-east of Ostrołęka, and 98 km (61 mi) north-east of Warsaw.