Sierżnia [ˈɕɛrʐɲa] is a village in the administrative district of Gmina Stryków, within Zgierz County, Łódź Voivodeship, in central Poland. It lies approximately 5 kilometres (3 mi) south-east of Stryków, 17 km (11 mi) east of Zgierz, and 16 km (10 mi) north-east of the regional capital Łódź.