Grodzisk Wielkopolski is a town in western Poland, in Greater Poland Voivodeship (Wielkopolskie), with a population of 13,703 (2006). It is 43 kilometres (27 mi) south-west of Poznań, the voivodeship capital. It is the seat of Grodzisk Wielkopolski County, and also of the smaller administrative district called Gmina Grodzisk Wielkopolski. It is situated on the Letnica River. The suffix "Wielkopolski" distinguishes it from the town of Grodzisk Mazowiecki in east-central Poland.

Greater Poland Voivodeship is a voivodeship, or province, in west-central Poland. It was created on 1 January 1999 out of the former Poznań, Kalisz, Konin, Piła and Leszno Voivodeships, pursuant to the Polish local government reforms adopted in 1998. The province is named after the region called Greater Poland or Wielkopolska. The modern province includes most of this historic region, except for some western parts.