Genesee County is a county in the U.S. state of Michigan. As of the 2010 census, the population was 425,790,[3] making it the fifth-most populous county in Michigan. The county seat and population center is Flint (birthplace of General Motors).[4] Genesee County comprises the Flint, MI Metropolitan Statistical Area and is included in the Detroit-Warren-Ann Arbor, MI Combined Statistical Area.