Resident Population in Genesee County, MI was 402.27900 Thous. of Persons in January of 2024, according to the United States Federal Reserve. Historically, Resident Population in Genesee County, MI reached a record high of 451.80000 in January of 1973 and a record low of 401.71100 in January of 2023. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Genesee County, MI - last updated from the United States Federal Reserve on April of 2026.