Livingston County is a county in the U.S. state of Michigan. As of the 2020 Census, the population was 193,866. It is part of the Detroit-Warren-Dearborn, MI Metropolitan Statistical Area. The county seat and most populous city is Howell. The county was platted in 1833, but for three years remained assigned to Shiawassee and Washtenaw counties for revenue, taxation and judicial matters. It was formally organized in 1836.