Malczyn [ˈmalt͡ʂɨn] is a village in the administrative district of Gmina Nasielsk, within Nowy Dwór County, Masovian Voivodeship, in east-central Poland. It lies approximately 6 kilometres (4 mi) west of Nasielsk, 17 km (11 mi) north of Nowy Dwór Mazowiecki, and 46 km (29 mi) north-west of Warsaw.