Janówek [jaˈnuvɛk] is a village in the administrative district of Gmina Tarczyn, within Piaseczno County, Masovian Voivodeship, in east-central Poland. It lies approximately 2 kilometres (1 mi) north-west of Tarczyn, 17 km (11 mi) south-west of Piaseczno, and 29 km (18 mi) south-west of Warsaw.