Mortąg [ˈmɔrtɔnk] is a village in the administrative district of Gmina Stary Dzierzgoń, within Sztum County, Pomeranian Voivodeship, in northern Poland. It lies approximately 3 kilometres (2 mi) south-east of Stary Dzierzgoń, 29 km (18 mi) east of Sztum, and 80 km (50 mi) south-east of the regional capital Gdańsk.