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.

Leszno is a historic city in western Poland, seat of Leszno County within the Greater Poland Voivodeship. It is the seventh-largest city in the province with an estimated population of 62,200, as of 2021.