Podmarszczyn [pɔdˈmarʂt͡ʂɨn] is a village in the administrative district of Gmina Dzierzążnia, within Płońsk County, Masovian Voivodeship, in east-central Poland. It lies approximately 9 kilometres (6 mi) south-west of Dzierzążnia, 16 km (10 mi) south-west of Płońsk, and 68 km (42 mi) north-west of Warsaw.