Gostyń County (Polish: powiat gostyński) is a unit of territorial administration and local government (powiat) in Greater Poland Voivodeship, west-central Poland.

It came into being on January 1, 1999, as a result of the Polish local government reforms passed in 1998.

Its administrative seat and largest town is Gostyń, which lies 59 kilometres (37 mi) south of the regional capital Poznań.

The county covers an area of 810.34 square kilometres (312.9 sq mi).

The county is subdivided into seven gminas (five urban-rural and two rural).