Zawidz Kościelny [ˈzavit͡s] is a village in Sierpc County, Masovian Voivodeship, in east-central Poland. It is the seat of the gmina (administrative district) called Gmina Zawidz. It lies approximately 16 kilometres (10 mi) south-east of Sierpc and 102 km (63 mi) north-west of Warsaw.