Czołnowo [t͡ʂɔu̯ˈnɔvɔ] is a settlement in the administrative district of Gmina Supraśl, within Białystok County, Podlaskie Voivodeship, in north-eastern Poland. It lies approximately 6 kilometres (4 mi) north-east of Supraśl and 21 km (13 mi) north-east of the regional capital Białystok.