Cass City is a village in Tuscola County in the Flint/Tri-Cities area of the U.S. state of Michigan. The population was 2,643 at the 2000 census, a 16.1% increase over its 1990 population of 2,276. However, the 2008 census estimate places the population at 2,493, a 5.68% reduction from the 2000 Census. It is located along the M-81 state trunkline approximately 4 miles west of that highway's intersection with M-53. The town is named after the nearby Cass River. It is currently within Michigan's 5th congressional district.