Allentown is a city in Lehigh County, Pennsylvania. It is the 233rd-largest city in the United States and, as of the 2020 census, has a total population of 125,845. Allentown is the fastest growing major city in Pennsylvania as well as the third-largest city overall in Pennsylvania, behind only Philadelphia and Pittsburgh in terms of total population. It is the county seat of Lehigh County and the largest city in the metropolitan area known as the Lehigh Valley, which had a population of 821,623 residents as of 2010. The city, founded in 1762, celebrated its 250th anniversary in 2012.
Located on the Lehigh River, Allentown is the largest of three adjacent cities in Lehigh and Northampton counties that join together with Carbon County to make up the Lehigh Valley region of eastern Pennsylvania. Allentown is approximately 55 miles north-northwest of Philadelphia, the sixth-most populous city in the U.S. 75 miles south-southeast of Scranton and the Wyoming Valley, 80 miles east-northeast of Harrisburg, the state capital, and 85 miles west of New York City, the nation's largest city.