Kozielsk [ˈkɔʑɛlsk] is a village in the administrative district of Gmina Kuczbork-Osada, within Żuromin County, Masovian Voivodeship, in north-central Poland. It lies approximately 2 kilometres (1 mi) east of Kuczbork-Osada, 12 km (7 mi) east of Żuromin, and 115 km (71 mi) north-west of Warsaw.