Gmina Krzywiń is an urban-rural gmina (administrative district) in Kościan County, Greater Poland Voivodeship, in west-central Poland. Its seat is the town of Krzywiń, which lies approximately 18 kilometres (11 mi) south-east of Kościan and 49 km (30 mi) south of the regional capital Poznań.
The gmina covers an area of 179.16 square kilometres (69.2 sq mi), and as of 2006 its total population is 9,892 (out of which the population of Krzywiń amounts to 1,547, and the population of the rural part of the gmina is 8,345).