Zalesie [zaˈlɛɕɛ] (German: Salleschen) is a village in the administrative district of Gmina Kozłowo, within Nidzica County, Warmian-Masurian Voivodeship, in northern Poland. It lies approximately 5 kilometres (3 mi) east of Kozłowo, 9 km (6 mi) south-west of Nidzica, and 55 km (34 mi) south of the regional capital Olsztyn.