Cassopolis is a village in the U.S. state of Michigan. As of the 2010 census, the village population was 14,275. It is the county seat of Cass County. The village and county are named after statesman Lewis Cass, a New Hampshire native and a prominent U.S. senator from Michigan prior to the American Civil War.
Cassopolis is part of the South Bend–Mishawaka, IN-MI, Metropolitan Statistical Area.
David F. Cargo (born 1929), liberal Republican governor of New Mexico from 1967—1971, was born in Dowagiac in Cass County.