Resident Population in Montgomery County, OH was 533.79600 Thous. of Persons in January of 2023, according to the United States Federal Reserve. Historically, Resident Population in Montgomery County, OH reached a record high of 608.41300 in January of 1970 and a record low of 531.95400 in January of 2018. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Montgomery County, OH - last updated from the United States Federal Reserve on May of 2024.