Annville Township is a township and census-designated place in Lebanon County, Pennsylvania, United States. The population was 4,767 at the 2010 census.
Annville Township was divided into North Annville Township and South Annville Township in 1845. In 1912, the new Annville Township was formed between the two to encompass the town of Annville.
Annville Township is located at 40°19′49″N 76°30′45″W (40.330162, -76.512533).
According to the United States Census Bureau, the township has a total area of 1.6 square miles (4.1 km2), of which, 1.6 square miles (4.1 km2) of it is land and 0.63% is water.
Annville has a humid continental climate and is classified "Dfa" on Köppen climate classification. Annville gets warm to hot summers and cold winters. Winters bring 40" of snow annually.
The township is bordered to the north and west by North Annville Township (3.2 mi), to the south and west by South Annville Township (3 mi), and to the east by Cleona (0.47 mi) and North Cornwall Township (0.25 mi).
As of the census of 2000, there were 4,518 people, 1,452 households, and 917 families residing in the township.