Harrison Township is in Hamilton County. It forms the northwest corner of Hamilton County with Indiana to the west and Morgan Township in Butler County to the north. Neighboring townships in Hamilton County are Crosby to the east and Whitewater to the south. Harrison Township was formed in 1853 with land formerly in Crosby and Whitewater townships. The city of Harrison was founded by Jonas Crane and surveyed in 1810. State Street in Harrison forms the Ohio-Indiana border.