Ościsłowo [ɔɕt͡ɕiˈswɔvɔ] is a village in the administrative district of Gmina Glinojeck, within Ciechanów County, Masovian Voivodeship, in north-central Poland.

According to the 1921 census, the village had a population of 345, entirely Polish by nationality and Roman Catholic by confession.

[2] During the German occupation of Poland (World War II), Ościsłowo was the site of large massacres, in which several hundreds of Poles were murdered as part of the Intelligenzaktion.

[3] Also several dozen disabled from the region were murdered in the village on 20 February 1940.

This Ciechanów County location article is a stub.