Maćkowa Ruda [mat͡ɕˈkɔva ˈruda], is a village in the administrative district of Gmina Krasnopol, within Sejny County, Podlaskie Voivodeship, in north-eastern Poland. It lies approximately 8 kilometres (5 mi) south of Krasnopol, 16 km (10 mi) south-west of Sejny, and 104 km (65 mi) north of the regional capital Białystok.