Kumajny [kuˈmai̯nɨ] is a village in the administrative district of Gmina Orneta, within Lidzbark County, Warmian-Masurian Voivodeship, in northern Poland. It lies approximately 9 kilometres (6 mi) north-east of Orneta, 28 km (17 mi) west of Lidzbark Warmiński, and 49 km (30 mi) north-west of the regional capital Olsztyn.

Before 1772 the area was part of Kingdom of Poland, and in 1772–1945 it belonged to Prussia and Germany (East Prussia).