Christian County is located in the southwestern part of the U.S. state of Missouri. As of the 2020 census, its population was 88,842. Its county seat is Ozark. The county was organized in 1859 and is named after Christian County, Kentucky, which in turn is named for William Christian, a Kentucky soldier of the American Revolutionary War.

William Christian was a military officer, planter and politician from the western part of the Colony of Virginia. He represented Fincastle County in the House of Burgesses and as relations with Britain soured, signed the Fincastle Resolutions. He later represented western Virginia in the Virginia Senate and founded Fort William, as well as helped negotiate the Treaty of Long Island of the Holston, which made peace between the Overmountain Men and Cherokees in 1777. He was killed in 1786 at the outset of the Northwest Indian War, leading an expedition against Native Americans near what is now Jeffersonville, Indiana.