Cornplanter Township is a township in Venango County, Pennsylvania, United States. The population was 2,317 at the 2020 census, a decrease from 2,487 at the 2010 and 2,687 at the 2000 census.

Venango County is a county in the Commonwealth of Pennsylvania. As of the 2020 census, the population was 50,454. Its county seat is Franklin. The county was created in 1800 and later organized in 1805. The county is part of the Northwest Pennsylvania region of the state.