Resident Population in Oregon County, MO was 8.69900 Thous. of Persons in January of 2024, according to the United States Federal Reserve. Historically, Resident Population in Oregon County, MO reached a record high of 11.04900 in January of 2011 and a record low of 8.61100 in January of 2020. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Oregon County, MO - last updated from the United States Federal Reserve on September of 2025.