County government Cities, towns, unincorporated communities, census-designated places There are 114 counties and one independent city in the U.S. state of Missouri . Following the Louisiana Purchase and the admittance of Louisiana into the United States in 1812, five counties were formed out of the Missouri Territory at the first general assembly: Cape Girardeau , New Madrid , Saint Charles , Saint Louis , and Ste. Genevieve . Most subsequent counties were apportioned from these five original counties. Six more counties were added through the 1836 Platte Purchase , the acquired lands of which formed the northwest tip of the state and consisted of Andrew , Atchison , Buchanan , Holt , Nodaway , and Platte counties. [ 1 ] In Missouri, the county level of government comes between those of the city and the state. Its primary responsibilities include maintaining roads, providing security, prosecuting criminals, and collecting taxes. Elected officials at this level include a sheriff , prosecuting attorney , and assessor . [ 2 ] Most of the counties in Missouri are named after politicians. One such county, Cass , was originally named Van Buren County after President Martin Van Buren , and was changed to its present name in support of Van Buren's Democratic opponent Lewis Cass during the presidential election of 1848 . Other counties are named after war heroes, natural resources, explorers, and former U.S. territories . [ 3 ] The city of St. Louis is an independent city, and is not within the limits of a county. Its residents voted to secede from St. Louis County in 1876. Throughout the United States, St. Louis is one of three independent cities outside the state of Virginia (the other two are Baltimore , Maryland, and Carson City , Nevada). [ 4 ] Population figures are based on the 2025 Census estimate. According to that census estimate, the population of Missouri is 6,270,541, an increase of 1.9% from 2020. The average population of Missouri's counties is 54,526 ; St. Louis County is the most populous (990,911), and Worth County is the least (1,914). The average land area is 599 sq mi (1,550 km 2 ) . The largest county is Texas County (1,179 sq mi, 3,054 km 2 ) and the smallest is St. Louis city (61.9 sq mi, 160 km 2 ). [ 5 ] [ 6 ] The Federal Information Processing Standard (FIPS) is used by the U.S. government to uniquely identify counties, and is provided for each entry. These codes link to the United States Census Bureau 's "quick facts" for each county. To distinguish from counties in other states, one must use Missouri's FIPS code, 29. For example, Adair County 's unique nationwide identifier is 29001. [ 7 ] Former county names List of townships in Missouri List of cities in Missouri List of U.S. counties by population Missouri census statistical areas Demographics of Missouri ↑ "Timeline of Missouri History: 1673–1799" . Missouri State Government Web . Retrieved October 10, 2009 . ↑ "County Government Links" . Missouri State Government Web. Archived from the original on May 23, 2009 . Retrieved October 10, 2009 . 1 2 3 4 5 6 "What are the Origins of Missouri Counties?" . Missouri State Government Web . Retrieved September 17, 2009 . ↑ "About St. Louis: Government" . City of St. Louis. Archived from the original on June 7, 2011 . Retrieved October 12, 2009 . ↑ U.S. Census Bureau Archived July 2, 2013, at the Wayback Machine , ("Missouri County Selection Map") ↑ "2020 Population and Housing State Data" . U.S. Census Bureau . Retrieved August 12, 2021 . 1 2 "EPA County FIPS Code Listing" . US Environmental Protection Agency. Archived from the original on March 21, 2014 . Retrieved September 27, 2009 . 1 2 3 "NACo – Find a county" . National Association of Counties. Archived from the original on August 28, 2009 . Retrieved September 17, 2009 . ↑ Beatty, Michael (2001). County Name Origins of the United States . McFarland Press. ISBN 0-7864-1025-6 . 1 2 Coulet du Gard, René; Coulet Western, Dominique (1981). The Handbook of American Counties, Parishes and Independent Cities . Editions des Deux Mondes. ISBN 0-939586-00-2 . ↑ "U.S. Census 2025 population estimates" . United States Census Bureau . Retrieved April 2, 2026 . ↑ Howard Louis Conard (1901). Encyclopedia of the history of Missouri . New York, Louisville [etc.] The Southern history company, Haldeman, Conard & co., proprietors. p. 68 . ↑ Missouri Atlas of Historical County Boundaries. "Missouri: Consolidated Chronology of State and County Boundaries" . The Newberry Library . Retrieved May 4, 2026 . ↑ Stevens, Walter B. (1921). Centennial history of Missouri (The Center State) One Hundred Years in the Union 1820–1921 . Chicago: Clarke Pub. Co. p. 72 . ↑ Stevens, Walter B. (1921). Centennial history of Missouri (The Center State) One Hundred Years in the Union 1820–1921 . Chicago: Clarke Pub. Co. p. 73 . Further reading

"Missouri County Government Overview" (PDF) . ce.naco.org . National Association of Counties. 2022 . Retrieved January 3, 2025 . Missouri Association of Counties Digitized 1930 Plat Books of Missouri Counties from University of Missouri Division of Special Collections, Archives, and Rare Books Geography Caves Government delegations History battles Civil War Tourist attractions Four State Area Mississippi Embayment Missouri Rhineland Northern Plains Platte Purchase St. Francois Mountains University City Maryland Heights St. Louis (City) St. Louis (County) Connecticut ( equiv. ) District of Columbia Northern Mariana Islands U.S. Virgin Islands United States Minor Outlying Islands Lists of counties of the United States by state Missouri counties Missouri geography-related lists Articles with short description Short description is different from Wikidata Use American English from June 2025 All Wikipedia articles written in American English Use mdy dates from April 2024 Webarchive template wayback links