Green Bay Township is a township in Clarke County, Iowa, USA. As of the 2000 census, its population was 232.
Green Bay Township covers an area of 36.56 square miles (94.7 km2) and contains no incorporated settlements. According to the USGS, it contains four cemeteries: Chaney, Ellis, Green Bay and Hebron.
The streams of Hoosier Creek and North Hoosier Creek run through this township.