Września County (Polish: powiat wrzesiński) 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 Września; the county is administered from the district office building.

The county covers an area of 704.19 square kilometres (271.9 sq mi).

These are listed in the following table, in descending order of population.