Sierżniki [ɕɛrʐˈniki] is a village in the administrative district of Gmina Chąśno, within Łowicz County, Łódź Voivodeship, in central Poland. It lies approximately 4 kilometres (2 mi) south of Chąśno, 8 km (5 mi) north of Łowicz, and 54 km (34 mi) north-east of the regional capital Łódź.