Mroczno [ˈmrɔt͡ʂnɔ] is a village in the administrative district of Gmina Grodziczno, within Nowe Miasto County, Warmian-Masurian Voivodeship, in northern Poland. It lies approximately 8 kilometres (5 mi) south-west of Grodziczno, 11 km (7 mi) south-east of Nowe Miasto Lubawskie, and 72 km (45 mi) south-west of the regional capital Olsztyn.