Cass County is a county located in the western part of the U.S. state of Missouri and is part of the Kansas City metropolitan area. As of the 2020 census, the population was 107,824. Its county seat is Harrisonville; however, the county contains a portion of Kansas City, Missouri. The county was organized in 1835 as Van Buren County, but was renamed in 1849 after U.S. Senator Lewis Cass of Michigan, who later became a presidential candidate.
