Cass City is a village in Elkland Township, Tuscola County in the Flint/Tri-Cities area of the U.S. state of Michigan. The population was 2,428 at the 2010 U.S. Census and 2,643 at the 2000 U.S. Census. It is located along M-81 approximately four miles (6.4 km) west of that highway's intersection with M-53. Cass City is surrounded by several communities including Colwood, Deford, Elmwood and Ellington.

The Cass River is a 61.5-mile-long (99.0 km) river in the Thumb region of the U.S. state of Michigan. It drains large portions of Sanilac and Tuscola counties and smaller portions of Genesee, Huron, Lapeer, and Saginaw counties.