Grodzisk Wielkopolski is a town located in western Poland within the Greater Poland Voivodeship (Wielkopolskie). It serves as the administrative seat for both Grodzisk County and the smaller district of Gmina Grodzisk Wielkopolski. The town is situated along the Letnica River.
As of 2006, the population of the town was recorded at 13,703. The suffix "Wielkopolski" in its name serves to distinguish it from the town of Grodzisk Mazowiecki, which is located in east-central Poland.