Grońsko [ˈɡrɔɲskɔ] is a village in the administrative district of Gmina Lwówek, within Nowy Tomyśl County, Greater Poland Voivodeship, in west-central Poland. It lies approximately 5 kilometres (3 mi) west of Lwówek, 13 km (8 mi) north of Nowy Tomyśl, and 55 km (34 mi) west of the regional capital Poznań.