Zaścianki [zaɕˈt͡ɕaŋki] is a village in the administrative district of Gmina Supraśl, within Białystok County, Podlaskie Voivodeship, in north-eastern Poland. It lies approximately 12 kilometres (7 mi) south-west of Supraśl and 5 km (3 mi) north-east of the regional capital Białystok.