Letniki [lɛtˈniki] is a village in the administrative district of Gmina Dobrzyniewo Duże, within Białystok County, Podlaskie Voivodeship, in north-eastern Poland. It lies approximately 6 kilometres (4 mi) north-east of Dobrzyniewo Duże and 15 km (9 mi) north-west of the regional capital Białystok.