Posey Township is one of six townships in Switzerland County, Indiana, United States. As of the 2020 census, its population was 1,576 and it contained 653 housing units.
The Merit-Tandy Farmstead was listed on the National Register of Historic Places in 1977.
According to the 2010 census, the township has a total area of , of which (or 95.98%) is land and (or 4.02%) is water.
(This list is based on USGS data and may include former settlements.)
The township contains these ten cemeteries: Antioch, Bark Works, Concord, Eastview, Grant Brothers, Jack, McNutt, Mead, Munger and Wigal.