Harleysville is a census-designated place (CDP) in Montgomery County, Pennsylvania, United States. The population was 9,286 at the 2010 census. It is located within Lower Salford Township. Harleysville was settled by Pennsylvania Dutch in the 18th century and was probably founded by the Harley family.
Harleysville is located at 40°16′46″N 75°23′12″W / 40.27944°N 75.38667°W / 40.27944; -75.38667 (40.279549, -75.386745).
According to the United States Census Bureau, the CDP has a total area of 4.2 square miles (11 km2), all of it land.