Osiek is a village in the administrative district of Gmina Joniec, within Pà Âoà Âsk County, Masovian Voivodeship, in east-central Poland.
This gentry village ("wieà  szlachecka", i.e., owned by a noble) became part of the in the second half of the XVI. Between 1975 and 1998, this place belonged to the Ciechanów Voivodeship.