Duchnów [ˈduxnuf] is a village in the administrative district of Gmina Wiązowna, within Otwock County, Masovian Voivodeship, in east-central Poland. It lies approximately 3 kilometres (2 mi) north-east of Wiązowna, 10 km (6 mi) north-east of Otwock, and 25 km (16 mi) east of Warsaw.