Charlevoix County is a county in the U.S. state of Michigan. As of the 2010 census, the population was 25,949. The county seat is Charlevoix. The county was named for Pierre François Xavier de Charlevoix, a Jesuit missionary in 1843. The county was originally set off in 1840 as Keskkauko, and name changed in 1843. It was later organized in 1869.