Długa [ˈdwuɡa] is a village in the administrative district of Gmina Sępopol, within Bartoszyce County, Warmian-Masurian Voivodeship, in northern Poland, close to the border with the Kaliningrad Oblast of Russia. It lies approximately 4 kilometres (2 mi) north of Sępopol, 16 km (10 mi) east of Bartoszyce, and 67 km (42 mi) north-east of the regional capital Olsztyn.