Ustronie [usˈtrɔɲɛ] is a village in the administrative district of Gmina Borek Wielkopolski, within Gostyń County, Greater Poland Voivodeship, in west-central Poland. It lies approximately 6 kilometres (4 mi) west of Borek Wielkopolski, 12 km (7 mi) east of Gostyń, and 59 km (37 mi) south of the regional capital Poznań.