Lansing is a city in Leavenworth County, Kansas, United States. It is situated along the west side of the Missouri River and Kansas-Missouri state border. As of the 2020 census, the population of the city was 11,239. It is the second most populous city of Leavenworth County and is a part of the Kansas City metropolitan area. The Lansing Correctional Facility, which includes the state's main maximum-security prison, is located in Lansing.

Leavenworth County is located in the U.S. state of Kansas and is part of the Kansas City metropolitan area. Its county seat and most populous city is Leavenworth. As of the 2020 census, the county population was 81,881. The county was named after Henry Leavenworth, a general in the Indian Wars who established Fort Leavenworth.