Fountain Hill is a borough in Lehigh County, Pennsylvania, United States. The population of Fountain Hill was 4,832 at the 2020 census, an increase over the figure of 4,597 tabulated in 2010. It is part of the Lehigh Valley metropolitan area, which had a population of 861,899 and was the 68th-most populous metropolitan area in the U.S. as of the 2020 census.