Wieczfnia Kościelna [ˈvjɛt͡ʂfɲa kɔɕˈt͡ɕɛlna] is a village in Mława County, Masovian Voivodeship, in east-central Poland. It is the seat of the gmina (administrative district) called Gmina Wieczfnia Kościelna. It lies approximately 13 kilometres (8 mi) north-east of Mława and 115 km (71 mi) north of Warsaw.