Sponsored Topics. Gratz is a borough in Dauphin County, Pennsylvania, United States. The population was 676 at the 2000 census. It is part of the Harrisburg–Carlisle Metropolitan Statistical Area. Gratz is located at 40°36′35″N 76°43′04″W / 40.609747°N 76.717835°W / 40.609747; -76.717835.