Ossa [ˈɔssa] is a village in the administrative district of Gmina Odrzywół, within Przysucha County, Masovian Voivodeship, in east-central Poland. It lies approximately 5 kilometres (3 mi) west of Odrzywół, 20 km (12 mi) north-west of Przysucha, and 86 km (53 mi) south-west of Warsaw.

During the January Uprising, on July 10, 1863, it was the site of the Battle of Ossa, in which Polish insurgents led by General Ludwik Żychliński defeated Russian troops.