Allentown (Pennsylvania Dutch: Allenschteddel, Allenschtadt, or Ellsdaun) is a city in Lehigh County, Pennsylvania, in the United States. The city has a population of 125,845 as of the 2020 census. It is the fastest-growing major city in Pennsylvania and the state’s third largest city, behind Philadelphia and Pittsburgh. It is the largest city in the Lehigh Valley, which has a population of 861,899 and is the 68th most populated metropolitan area in the U.S. as of 2020. Allentown was founded in 1762 and is the county seat of Lehigh County.
Located on the Lehigh River, Allentown is the largest of three adjacent cities (Allentown, Bethlehem, and Easton) in Lehigh and Northampton counties that join with Carbon County in Pennsylvania’s Coal Region and Warren County in northwest New Jersey to form the Lehigh Valley metropolitan area. Allentown is approximately 52 miles (84 km) north-northwest of Philadelphia and 92 miles (148 km) west of New York City.