Mostniki [mɔstˈniki] is a settlement in the administrative district of Gmina Dobiegniew, within Strzelce-Drezdenko County, Lubusz Voivodeship, in western Poland.

It lies approximately 16 kilometres (10 mi) north-east of Dobiegniew, 34 km (21 mi) north-east of Strzelce Krajeńskie, and 58 km (36 mi) north-east of Gorzów Wielkopolski.