Ostrów-Mausz [ˈɔstruf ˈmauʂ] is a village in the administrative district of Gmina Sulęczyno, within Kartuzy County, Pomeranian Voivodeship, in northern Poland. It lies approximately 5 km (3 mi) south-west of Sulęczyno, 35 km (22 mi) south-west of Kartuzy, and 62 km (39 mi) west of the regional capital Gdańsk.

For details of the history of the region, see History of Pomerania.