Ostrowiec [ɔsˈtrɔvjɛt͡s] (German: Sagemühl) is a village in the administrative district of Gmina Wałcz, within Wałcz County, West Pomeranian Voivodeship, in north-western Poland. It lies approximately 6 kilometres (4 mi) north-east of Wałcz and 130 km (81 mi) east of the regional capital Szczecin.

The village has a population of 260.