Bartniki [bartˈniki] is a village in the administrative district of Gmina Puszcza Mariańska, within Żyrardów County, Masovian Voivodeship, in east-central Poland. It lies approximately 8 kilometres (5 mi) north-west of Puszcza Mariańska, 14 km (9 mi) west of Żyrardów, and 57 km (35 mi) south-west of Warsaw.