Kopijki [kɔˈpii̯ki] is a village in the administrative district of Gmina Prostki, within Ełk County, Warmian-Masurian Voivodeship, in northern Poland. It lies approximately 10 kilometres (6 mi) north-east of Prostki, 15 km (9 mi) south-east of Ełk, and 135 km (84 mi) east of the regional capital Olsztyn.