Macungie is borough in Lehigh County, Pennsylvania, United States, its second oldest. As of the 2020 census, Macungie had a population of 3,257. Macungie is a suburb of Allentown, and part of the Lehigh Valley metropolitan area, which had a population of 861,899 and was the 68th-most populous metropolitan statistical area in the U.S. as of the 2020 census.