Kobylin [kɔˈbɨlin] is a village in the administrative district of Gmina Prostki, within Ełk County, Warmian-Masurian Voivodeship, in northern Poland. It lies approximately 4 kilometres (2 mi) west of Prostki, 14 km (9 mi) south of Ełk, and 125 km (78 mi) east of the regional capital Olsztyn.