Resident Population in Montgomery County, PA was 868.74200 Thous. of Persons in January of 2023, according to the United States Federal Reserve. Historically, Resident Population in Montgomery County, PA reached a record high of 868.74200 in January of 2023 and a record low of 624.08000 in January of 1970. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Montgomery County, PA - last updated from the United States Federal Reserve on May of 2024.