Sepno [ˈsɛpnɔ] is a village in the administrative district of Gmina Kamieniec, within the Grodzisk Wielkopolski County, Greater Poland Voivodeship, in west-central Poland. It lies approximately 17 kilometres (11 mi) southeast of Grodzisk Wielkopolski and 38 km (24 mi) southwest of the regional capital Poznań.