Zalewo [zaˈlɛvɔ] (German: Saalfeld in Ostpreußen) is a town in Iława County, Warmian-Masurian Voivodeship, Poland, with 2,977 inhabitants (2008).
The settlement was founded in the 13th century and was granted town rights in 1305.
During the Napoleonic Wars in 1807 Polish soldiers of General Jan Henryk Dąbrowski were quartered in the town.
Before 1945 the town German-settled and part of Germany, located in Kreis Mohrungen, province of East Prussia. During World War II it was destroyed in 70%.