Koźminek [kɔʑˈminɛk] is a town in Kalisz County, Greater Poland Voivodeship, in west-central Poland. It serves as the seat of the gmina (administrative district) called Gmina Koźminek. It lies approximately 17 kilometres (11 mi) east of Kalisz and 118 km (73 mi) south-east of the regional capital Poznań.

The town has a population of 1,800.