Resident Population in Lehigh County, PA was 385.65500 Thous. of Persons in January of 2024, according to the United States Federal Reserve. Historically, Resident Population in Lehigh County, PA reached a record high of 385.65500 in January of 2024 and a record low of 255.30400 in January of 1970. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Lehigh County, PA - last updated from the United States Federal Reserve on April of 2026.