Częstoniew [t͡ʂɛ̃sˈtɔɲɛf] is a village in the administrative district of Gmina Grójec, within Grójec County, Masovian Voivodeship, in east-central Poland. It lies approximately 7 kilometres (4 mi) east of Grójec and 39 km (24 mi) south of Warsaw.