Hornostaje [xɔrnɔsˈtajɛ] is a village in the administrative district of Gmina Mońki, within Mońki County, Podlaskie Voivodeship, in north-eastern Poland. It lies approximately 6 kilometres (4 mi) north of Mońki and 45 km (28 mi) north-west of the regional capital Białystok.