Greenbush is an unincorporated town in Sheboygan County, Wisconsin, United States.

The unincorporated community of German Corners is also located in the town.

Greenbush hosts the Kettle Moraine Correctional Institution.

The 2020 census population of the city included 438 people incarcerated in adult correctional facilities.

12.5% of all households were made up of individuals, and 4.9% had someone living alone who was 65 years of age or older.