List of counties in Missouri


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, St. [Charles County, Missouri|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.
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 Sheriffs in [the United States|sheriff], prosecuting attorney, and assessor.
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 1848 [United States presidential election|presidential election of 1848]. Other counties are named after war heroes, natural resources, explorers, and former U.S. territories.
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.
Population figures are based on the 2024 Census estimate. According to that census estimate, the population of Missouri is 6,245,466, an increase of 1.5% from 2020. The average population of Missouri's counties is 54,308; St. Louis County is the most populous, and Worth County is the least. The average land area is. The largest county is Texas County and the smallest is St. Louis city.
The Federal Information Processing Standard is used by the U.S. government to uniquely identify counties, and is provided for each entry. These codes link to the Census Bureau">United States Census">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.

Counties

Former county names

CountyEtymologyChanged to
Allen County
Unknown
Atchison County in 1845
Ashley CountyWilliam Henry Ashley, early settlerTexas County in 1845 upon organization
Decatur CountyStephen Decatur, American naval officerOzark County in 1845
Highland County
Unknown
Sullivan County in 1845 upon organization
Kinderhook CountyKinderhook, New York, birthplace of Martin Van BurenCamden County in 1843
Lillard CountyJames Lillard of Tennessee, who served in the first state legislature of MissouriLafayette County in 1825
Niangua CountyNiangua River, a tributary of the Osage River – "niangua" comes from the Native American word nehemgar, which means "a river of numerous springs or sources"Dallas County in 1844 because of the difficulty in pronouncing and spelling Niangua
Seneca CountySeneca Nation, a group of Native Americans from New YorkMcDonald County in 1847 upon organization
Van Buren CountyMartin Van Buren, eighth President of the United States and also Vice President under Andrew JacksonCass County in 1849 in honor of Van Buren's opponent in the presidential election of 1848