West Cornwall Township is a township in Lebanon County, Pennsylvania, United States. It is part of the Lebanon, PA Metropolitan Statistical Area. The population was 1,987 at the 2020 census. According to the United States Census Bureau, the township has a total area of 8.7 square miles, all land. The township includes the unincorporated communities of Q…West Cornwall Township is a township in Lebanon County, Pennsylvania, United States. It is part of the Lebanon, PA Metropolitan Statistical Area. The population was 1,987 at the 2020 census. According to the United States Census Bureau, the township has a total area of 8.7 square miles, all land. The township includes the unincorporated communities of Quentin in the northeast and Mount Gretna Heights in the southwest.