Zionsville is a village mostly in Upper Milford Township in Lehigh County, Pennsylvania with parts of the village located in Lower Milford Township. The West Branch Hosensack Creek forms its natural southeastern boundary and drains it via the Hosensack Creek to the Perkiomen Creek. Zionsville is part of the Lehigh Valley, which has a population of 861,899 and is the 68th most populated metropolitan area in the U.S. as of the 2020 census. Its ZIP Code is 18092.