Białężyn [bjaˈwɛ̃ʐɨn] is a village in the administrative district of Gmina Murowana Goślina, within Poznań County, Greater Poland Voivodeship, in west-central Poland. It lies approximately 8 kilometres (5 mi) north of Murowana Goślina (on the road to Oborniki) and 27 km (17 mi) north of the regional capital Poznań.

The village has a church whose history goes back to 1725, when the demolished church of Słomowo was re-erected in Białężyn.