Resident Population in Monroe County, MI was 155.04500 Thous. of Persons in January of 2023, according to the United States Federal Reserve. Historically, Resident Population in Monroe County, MI reached a record high of 155.64600 in January of 2021 and a record low of 119.21500 in January of 1970. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Monroe County, MI - last updated from the United States Federal Reserve on May of 2024.