Dłużec [ˈdwuʐɛt͡s] is a village in the administrative district of Gmina Piecki, within Mrągowo County, Warmian-Masurian Voivodeship, in northern Poland. It lies approximately 7 kilometres (4 mi) west of Piecki, 12 km (7 mi) south of Mrągowo, and 50 km (31 mi) east of the regional capital Olsztyn.