Zielonka is a town in Wołomin County, Masovian Voivodeship, Poland, with 17,398 inhabitants. It is located about 13 km to the north-east of the centre of Warsaw. Zielonka borders Warsaw and several other towns of the Warsaw metropolitan area: Ząbki and Marki in the west, Kobyłka in the north, and Sulejówek in the south. It was granted town rights in 1960.