Mission Hills is a city in Johnson County, Kansas, United States, and part of the Kansas City Metropolitan Area. As of the 2020 census, the population of the city was 3,594. The east city limits is the Kansas-Missouri state line at State Line Road. Mission Hills was originally developed by noted Kansas City developer J. C. Nichols beginning in the 1920s as part of his Country Club District plan.

Johnson County is a county in the U.S. state of Kansas, along the border of the state of Missouri. Its county seat is Olathe. As of the 2020 census, the population was 609,863, the most populous county in Kansas. The county was named after Thomas Johnson, a Methodist missionary who was one of the state's first settlers. Largely suburban, the county contains a number of suburbs of Kansas City, Missouri, including Overland Park, a principal city of and second most populous city in the Kansas City Metropolitan Area.