Harrison Township is one of four townships in Blackford County, Indiana. As of the 2020 census, its population was 2,353 and it contained 1,155 housing units. The township was named after William Henry Harrison, hero of the Battle of Tippecanoe, former governor of the Indiana Territory, and ninth President of the United States.

Blackford County is located in the east central portion of the U.S. state of Indiana. The county is named for Judge Isaac Blackford, who was the first speaker of the Indiana General Assembly and a long-time chief justice of the Indiana Supreme Court. Created in 1838, Blackford County is divided into four townships, and its county seat is Hartford City. Two incorporated cities and one incorporated town are located within the county. The county is also the site of numerous unincorporated communities and ghost towns. Occupying only 165.58 square miles (428.9 km2), Blackford County is the fourth smallest county in Indiana. As of the 2020 census, the county's population was 12,112. Based on population, the county is the 8th smallest county of the 92 in Indiana. Although no interstate highways are located in Blackford County, three Indiana state roads cross the county, and an additional state road is located along the county's southeast border. The county has two railroad lines. A north–south route crosses the county, and intersects with a second railroad line that connects Hartford City with communities to the west.