Chapman Township is a township in Snyder County, Pennsylvania, United States. The population was 1,426 at the 2000 census.

According to the United States Census Bureau, the township has a total area of 13.3 square miles (34 km2), all of it land.

Chapman Township is bordered by Washington Township to the northwest, Union Township to the northeast, the Susquehanna River to the east, Juniata County to the south and Perry Township to the west.

The census-designated place of Port Trevorton lies partially in the northeast corner of the township along the Susquehanna River and U.S. Route 15.