Slatington is a borough in Lehigh County, Pennsylvania. As of the 2010 census, it had a population of 4,232. Slatington is located northwest of Allentown and Bethlehem. Slatington is part of the Lehigh Valley metropolitan area, which had a population of 861,899 and was thus the 68th most populous metropolitan area in the U.S. as of the 2020 census.