Marchewki [marˈxɛfki] is a village in the administrative district of Gmina Prostki, within Ełk County, Warmian-Masurian Voivodeship, in northern Poland. It lies approximately 8 kilometres (5 mi) south-west of Prostki, 18 km (11 mi) south of Ełk, and 122 km (76 mi) east of the regional capital Olsztyn.