Kansas's 3rd congressional district is a congressional district in the U.S. state of Kansas. Located in eastern Kansas, the district encompasses all of Anderson, Franklin, Johnson and Miami counties and parts of Wyandotte County. The district includes most of the Kansas side of the Kansas City metropolitan area, including all of Overland Park, Leawood, Lenexa, Shawnee, Gardner, and Olathe and parts of Kansas City.

Anderson County is a county located in East Central Kansas, in the Central United States. Its county seat and most populous city is Garnett. As of the 2020 census, the county population was 7,836. The county was named for Joseph C. Anderson, a Kansas territorial legislator and border ruffian during the "Bleeding Kansas" era.