Neffs is a small village located mainly in North Whitehall Township but also in Washington Township in Lehigh County, Pennsylvania. It is part of the Lehigh Valley, which has a population of 861,899 and is the 68th most populous metropolitan area in the U.S. as of the 2020 census. Neffs is located at the junction of Pennsylvania Routes 873 and 329, approximately one mile north of Schnecksville. The U.S. Postal Code (ZIP code) for Neffs is 18065. It is in the 610 area code and is served by the 767 exchange in Slatington.