Płonka Kościelna [ˈpwɔŋka kɔɕˈt͡ɕɛlna] is a village in the administrative district of Gmina Łapy, within Białystok County, Podlaskie Voivodeship, in north-eastern Poland. It lies approximately 4 kilometres (2 mi) north-west of Łapy and 26 km (16 mi) south-west of the regional capital Białystok.