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, 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]

Independent city and Counties of Missouri
AT HO ND AN BH PL CY CT DK GY WO HA DV CD RY CR LV GN ME PM SV LI CN RH MC AD SR SD CK KX LW SH MN MR RS AU PI LN MY CW BN HW SA LF JK CS JO PE CP MG MO CO ML OS MA GA WN CH FK SL ←LC JE SG PY SF MI IR WA CF PH PU CM HI BE HE BA CL VE CE BT DD PK DA GR XN WB LA WR DG TX DT SN RN WY BO CG ST SC MS NM PS DU BU CA RI OR HL OZ TA SE LR JA NN BY MD
Location	State of Missouri
Number	114 counties 1 independent city
Populations	1,872 (Worth) – 992,929 (St. Louis)
Areas	266 square miles (690 km2) (Worth) – 1,179 square miles (3,050 km2) (Texas)
Government	County government
Subdivisions	cities, towns, unincorporated communities, census designated place

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 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 (992,929), and Worth County is the least (1,872). The average land area is 599 sq mi (1,550 km²). The largest county is Texas County (1,179 sq mi, 3,054 km²) and the smallest is St. Louis city (61.9 sq mi, 160 km²).^[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]

Counties

County	FIPS code[7]	County seat[8]	Est.[8]	Formed from[3]	Etymology[3][9][10]	Population[11]	Area[8]	Map
Adair County	001	Kirksville	1841	Macon County	John Adair (1757–1840), pioneer, soldier, and seventh Governor of Kentucky	25,660	568 sq mi (1,471 km2)
Andrew County	003	Savannah	1841	Part of the Platte Purchase	Andrew Jackson Davis , a prominent citizen of St. Louis	18,091	435 sq mi (1,127 km2)
Atchison County	005	Rock Port	1843	Holt County, part of the Platte Purchase	U.S. Senator David Rice Atchison (1807–1886), a Democrat from Missouri	5,139	545 sq mi (1,412 km2)
Audrain County	007	Mexico	1831	Callaway, Monroe and Ralls counties	James Hunter Audrain, a War of 1812 colonel Missouri State Legislator	24,304	693 sq mi (1,795 km2)
Barry County	009	Cassville	1835	Greene County	William Taylor Barry (1784–1835), jurist and United States Postmaster General	35,618	779 sq mi (2,018 km2)
Barton County	011	Lamar	1855	Jasper County	U.S. Senator David Barton (1783–1837), one of the first senators from Missouri	11,717	594 sq mi (1,538 km2)
Bates County	013	Butler	1841	Van Buren (now Cass) County	Frederick Bates (1777–1825), the second governor of Missouri	16,394	848 sq mi (2,196 km2)
Benton County	015	Warsaw	1835	Pettis and Greene counties	Thomas Hart Benton (1782–1858), U.S. Senator from Missouri	20,614	706 sq mi (1,829 km2)
Bollinger County	017	Marble Hill	1851	Cape Girardeau, Madison, Stoddard and Wayne counties	George Frederick Bollinger (1770–1842), early settler of Missouri	10,610	621 sq mi (1,608 km2)
Boone County	019	Columbia	1820	Howard County	Daniel Boone (1734–1820), American pioneer and hunter	192,154	685 sq mi (1,774 km2)
Buchanan County	021	Saint Joseph	1838	Part of the Platte Purchase	James Buchanan (1791–1868), 15th President of the United States	83,574	410 sq mi (1,062 km2)
Butler County	023	Poplar Bluff	1849	Wayne County	William O. Butler (1791–1880), U.S. Representative from Kentucky and vice-presidential nominee under Lewis Cass	41,814	698 sq mi (1,808 km2)
Caldwell County	025	Kingston	1836	Ray County	Disputed; either John Caldwell, an Indian scout and friend of respected Colonel Alexander William Doniphan; John Caldwell, Lieutenant Governor of Kentucky; or Mathew Caldwell, a signer of the Texas Declaration of Independence	9,000	429 sq mi (1,111 km2)
Callaway County	027	Fulton	1821	Boone, Howard and Montgomery counties	James Callaway (1783–1815), soldier during the War of 1812 and grandson of Daniel Boone	45,126	839 sq mi (2,173 km2)
Camden County	029	Camdenton	1841	Benton, Morgan and Pulaski counties	Charles Pratt, 1st Earl Camden (1714–1794), an English lawyer, judge, Whig politician, and proponent of civil liberties	44,135	655 sq mi (1,696 km2)
Cape Girardeau County	031	Jackson	1812	One of the five original counties	A rock promontory over the Mississippi River and Ensign Sieur Jean Baptiste de Girardot, a French officer and early explorer of the region	83,658	579 sq mi (1,500 km2)
Carroll County	033	Carrollton	1833	Ray County	Charles Carroll (1737–1832), delegate to the Continental Congress and U.S. Senator for Maryland	8,414	695 sq mi (1,800 km2)
Carter County	035	Van Buren	1859	Oregon, Reynolds, Ripley and Shannon counties	Zimri Carter (1794-1872), a pioneering settler	5,359	508 sq mi (1,316 km2)
Cass County	037	Harrisonville	1833	Jackson County	Lewis Cass (1782–1866), senator from Michigan	113,873	699 sq mi (1,810 km2)
Cedar County	039	Stockton	1845	Dade and St. Clair counties	Named for the abundance of Eastern Red Cedar trees	15,023	476 sq mi (1,233 km2)
Chariton County	041	Keytesville	1821	Howard County	Chariton River, a tributary of the Missouri River, whose naming origin is disputed	7,397	756 sq mi (1,958 km2)
Christian County	043	Ozark	1859	Greene, Taney and Webster counties	William Christian (1743–1786), colonel in the American Revolution	96,045	563 sq mi (1,458 km2)
Clark County	045	Kahoka	1836	Lewis County	William Clark (1770–1838), American explorer, soldier, Indian agent, and territorial governor	6,623	507 sq mi (1,313 km2)
Clay County	047	Liberty	1822	Ray County	Henry Clay (1777–1852), American Senator and orator from Kentucky	263,370	396 sq mi (1,026 km2)
Clinton County	049	Plattsburg	1833	Clay County	George Clinton (1739–1812), soldier and Governor of New York, considered one of the Founding Fathers of the United States	21,721	419 sq mi (1,085 km2)
Cole County	051	Jefferson City	1820	Cooper County	Stephen Cole, pioneering settler	77,625	392 sq mi (1,015 km2)
Cooper County	053	Boonville	1818	Howard County	Sarshel Benjamin Cooper, pioneering settler	17,122	565 sq mi (1,463 km2)
Crawford County	055	Steelville	1829	Gasconade County	William H. Crawford (1772–1834), U.S. Senator from Georgia, U.S. Secretary of Treasury, and judge	22,808	743 sq mi (1,924 km2)
Dade County	057	Greenfield	1841	Barry and Polk counties	Major Francis L. Dade (1793?–1835), Major in the U.S. 4th Infantry Regiment, United States Army, during the Second Seminole War	7,622	490 sq mi (1,269 km2)
Dallas County	059	Buffalo	1841	Polk County	George M. Dallas (1792–1864), U.S. Vice President under James K. Polk	17,877	542 sq mi (1,404 km2)
Daviess County	061	Gallatin	1836	Ray County	Joseph Hamilton Daveiss (1774–1811), commanded the Dragoons of the Indiana Militia at the Battle of Tippecanoe	8,541	567 sq mi (1,469 km2)
DeKalb County	063	Maysville	1843	Clinton County	Johann de Kalb (1721–1780), a German soldier who served as a major general in the Continental Army during the American Revolutionary War	9,884	424 sq mi (1,098 km2)
Dent County	065	Salem	1851	Crawford and Shannon counties	James Dent, pioneering settler	14,721	754 sq mi (1,953 km2)
Douglas County	067	Ava	1857	Ozark County	Stephen A. Douglas (1813–1861), American Senator from Illinois, and the Democratic nominee for President in 1860	12,290	815 sq mi (2,111 km2)
Dunklin County	069	Kennett	1843	Stoddard County	Daniel Dunklin (1790–1844), fifth governor of Missouri	27,002	546 sq mi (1,414 km2)
Franklin County	071	Union	1818	St. Louis County	Benjamin Franklin (1706–1790), writer, publisher, orator, and one of the Founding Fathers of the United States	107,256	922 sq mi (2,388 km2)
Gasconade County	073	Hermann	1821	Franklin County	Gasconade River, a tributary of the Missouri River; the river probably derives its name from the French word "gascon" which means braggart, and could be an old satirical name describing those who boast about their adventures upon return to St. Louis	14,655	520 sq mi (1,347 km2)
Gentry County	075	Albany	1841	Clinton County	Richard Gentry (1788–1837), a distinguished American military colonel in the Seminole Wars	6,298	492 sq mi (1,274 km2)
Greene County	077	Springfield	1833	Crawford and Wayne counties	Nathanael Greene (1742–1786), a major general of the Continental Army in the American Revolutionary War	307,942	675 sq mi (1,748 km2)
Grundy County	079	Trenton	1839	Livingston County	Felix Grundy (1777–1840), U.S. Congressman and U.S. Senator from Tennessee who also served as the 13th Attorney General of the United States	9,766	436 sq mi (1,129 km2)
Harrison County	081	Bethany	1843	Daviess County	Albert G. Harrison (1800–1839), U.S. Representative from Missouri	8,186	725 sq mi (1,878 km2)
Henry County	083	Clinton	1834	Lillard (now Lafayette) County	Patrick Henry (1736–1799), first post-colonial Governor of Virginia and prominent figure in the American Revolution	22,575	702 sq mi (1,818 km2)
Hickory County	085	Hermitage	1845	Benton and Polk counties	Andrew Jackson (1767–1845), seventh U.S. President, who was nicknamed "Old Hickory" during his military service	8,766	399 sq mi (1,033 km2)
Holt County	087	Oregon	1841	Part of the Platte Purchase	David Rice Holt, Missouri State Representative	4,241	462 sq mi (1,197 km2)
Howard County	089	Fayette	1816	St. Charles and St. Louis counties	Benjamin Howard (1760–1814), a Congressman from Kentucky, governor of Missouri Territory and a brigadier general in the War of 1812	10,150	466 sq mi (1,207 km2)
Howell County	091	West Plains	1857	Oregon County	Disputed – Josiah Howell, pioneering settler	40,762	928 sq mi (2,404 km2)
Iron County	093	Ironton	1857	Madison, Reynolds, St. Francois, Washington and Wayne counties	The abundance of iron ore in the area	9,420	551 sq mi (1,427 km2)
Jackson County	095	Independence, Kansas City	1826	Lillard (now Lafayette) County	Andrew Jackson (1767–1845), U.S. Senator from Tennessee and later 7th President of the United States from 1829 to 1837	727,362	605 sq mi (1,567 km2)
Jasper County	097	Carthage	1841	Barry County	William Jasper (c. 1750–1779), a noted American soldier in the Revolutionary War	126,479	640 sq mi (1,658 km2)
Jefferson County	099	Hillsboro	1818	St. Louis and Sainte Genevieve counties	Thomas Jefferson (1743–1826), third President of the United States, principal author of the Declaration of Independence, and one of the most influential Founding Fathers	231,888	657 sq mi (1,702 km2)
Johnson County	101	Warrensburg	1834	Lillard (now Lafayette) County	Richard M. Johnson (1780–1850), ninth Vice President of the United States, serving in the administration of Martin Van Buren	55,880	831 sq mi (2,152 km2)
Knox County	103	Edina	1843	Scotland County	Henry Knox (1750–1806) an American bookseller from Boston who became the chief artillery officer of the Continental Army and later the nation's first Secretary of War	3,740	506 sq mi (1,311 km2)
Laclede County	105	Lebanon	1849	Camden, Pulaski and Wright counties	Pierre Laclede (1729–1778), founder of St. Louis, Missouri	36,738	766 sq mi (1,984 km2)
Lafayette County	107	Lexington	1821	Cooper County	Gilbert du Motier, the Marquis de Lafayette (1757–1834), French military officer and general in the American Revolutionary War	33,511	629 sq mi (1,629 km2)
Lawrence County	109	Mount Vernon	1843	Barry and Dade counties	James Lawrence (1781–1813), an American naval officer best known for his last words "Don't give up the ship!"	39,151	613 sq mi (1,588 km2)
Lewis County	111	Monticello	1833	Marion County	Meriwether Lewis (1774–1809), explorer and governor of the Louisiana Territory	9,852	505 sq mi (1,308 km2)
Lincoln County	113	Troy	1818	St. Charles County	Disputed; either Lincoln County, Kentucky (birthplace of Christopher Clark, a Missouri legislator who advocated for the county's creation),[12] or for Benjamin Lincoln (1733–1810), an American revolutionary war general	65,888	630 sq mi (1,632 km2)
Linn County	115	Linneus	1837	Chariton County	Lewis F. Linn (1796–1843), a Jacksonian Democratic U.S. Senator for Missouri	11,910	620 sq mi (1,606 km2)
Livingston County	117	Chillicothe	1837	Carroll County	Edward Livingston (1764–1836), a prominent American jurist and statesman, influential in the drafting of the Louisiana Civil Code of 1825, a civil code based largely on the Napoleonic Code	14,658	535 sq mi (1,386 km2)
Macon County	121	Macon	1837	Chariton and Randolph counties	Nathaniel Macon (1758–1837), member of the United States House of Representatives from 1791 to 1815 who briefly served in the American Revolutionary War	15,177	804 sq mi (2,082 km2)
Madison County	123	Fredericktown	1818	Cape Girardeau and Sainte Genevieve counties	James Madison (1751–1836), politician and political philosopher who served as the fourth President of the United States, and one of the Founding Fathers of the United States	12,852	497 sq mi (1,287 km2)
Maries County	125	Vienna	1855	Osage and Pulaski counties	Maries River, possibly a corruption of the French word marais meaning "marsh" or "swamp"	8,506	528 sq mi (1,368 km2)
Marion County	127	Palmyra	1826	Ralls County	Francis Marion (1732–1795), a military officer who served in the American Revolutionary War	28,425	438 sq mi (1,134 km2)
McDonald County	119	Pineville	1847	Newton County	Alexander McDonald, American Revolutionary War sergeant	24,054	540 sq mi (1,399 km2)
Mercer County	129	Princeton	1845	Grundy County	John F. Mercer (1759–1821), an American lawyer, planter, and Governor of Maryland	3,452	454 sq mi (1,176 km2)
Miller County	131	Tuscumbia	1837	Cole and Pulaski counties	John Miller (1781–1846), an American publisher and politician from St. Louis, Missouri. He was the fourth Governor of Missouri and represented Missouri in the U.S. House	25,668	592 sq mi (1,533 km2)
Mississippi County	133	Charleston	1842	Scott County	Mississippi River, the second-longest river in the United States which forms Missouri's eastern border	11,750	413 sq mi (1,070 km2)
Moniteau County	135	California	1845	Cole and Morgan counties	Moniteau Creek; "moniteau" is a French spelling of manitou, the Algonquian Great Spirit	15,294	417 sq mi (1,080 km2)
Monroe County	137	Paris	1831	Ralls County	James Monroe (1758–1831), fifth President of the United States who crafted the Missouri Compromise	8,890	646 sq mi (1,673 km2)
Montgomery County	139	Montgomery City	1818	St. Charles County	Richard Montgomery (1738–1775), an Irish-born soldier who first served in the British Army and later became a brigadier-general in the Continental Army during the Revolutionary War	11,511	539 sq mi (1,396 km2)
Morgan County	141	Versailles	1833	Cooper County	Daniel Morgan (c. 1736–1802), American pioneer, soldier, and United States Representative from Virginia	22,399	598 sq mi (1,549 km2)
New Madrid County	143	New Madrid	1812	One of the five original counties	Madrid, Spain	15,212	678 sq mi (1,756 km2)
Newton County	145	Neosho	1838	Barry County	John Newton (1755–1780), legendary soldier of the American Revolution	61,519	626 sq mi (1,621 km2)
Nodaway County	147	Maryville	1843	Andrew County, the Platte Purchase	Nodaway River, a 120-mile (190 km) long river in southwest Iowa and northwest Missouri	20,503	877 sq mi (2,271 km2)
Oregon County	149	Alton	1841	Ripley County	Oregon Territory	8,699	792 sq mi (2,051 km2)
Osage County	151	Linn	1841	Gasconade County	Osage River, a 360 miles (580 km) long tributary of the Missouri River in central Missouri; the name of the river is probably derived from a French corruption of "Washazhe" – the name of the Osage Native Americans	13,478	606 sq mi (1,570 km2)
Ozark County	153	Gainesville	1841	Taney County	Ozark Mountains – Ozark is the anglicized form of the French "aux arcs", an abbreviation of "Aux Arkansas", which means in the county of Arkansas	9,090	747 sq mi (1,935 km2)
Pemiscot County	155	Caruthersville	1851	New Madrid County	An American Indian word meaning "liquid mud"	14,407	493 sq mi (1,277 km2)
Perry County	157	Perryville	1821	Sainte Genevieve County	Oliver Hazard Perry (1785–1819), naval officer in the War of 1812 against Britain, earned the title "Hero of Lake Erie" for leading American forces in a decisive naval victory at the Battle of Lake Erie	19,100	475 sq mi (1,230 km2)
Pettis County	159	Sedalia	1833	Cooper and Saline counties	Spencer Darwin Pettis (1802–1831), U.S. Representative from Missouri	43,791	685 sq mi (1,774 km2)
Phelps County	161	Rolla	1857	Crawford County	John S. Phelps (1814–1886), a politician, soldier during the American Civil War, and twenty-third Governor of Missouri	45,672	673 sq mi (1,743 km2)
Pike County	163	Bowling Green	1818	St. Charles County	Zebulon Pike (1778–1813), American soldier and explorer for whom Pikes Peak in Colorado is also named	17,961	673 sq mi (1,743 km2)
Platte County	165	Platte City	1838	Part of the Platte Purchase	Platte River, a tributary of the Missouri River, which is in turn named for the French word "platte" meaning flat or shallow	113,207	420 sq mi (1,088 km2)
Polk County	167	Bolivar	1835	Greene County	James K. Polk (1795–1849), 11th President of the United States	33,070	637 sq mi (1,650 km2)
Pulaski County	169	Waynesville	1833	Crawford County	Kazimierz Pulaski (1745–1779), Polish soldier of fortune in the American Revolutionary War, he saved the life of George Washington and became a general in the Continental Army	53,964	547 sq mi (1,417 km2)
Putnam County	171	Unionville	1843	Adair and Sullivan counties	Israel Putnam (1718–1790), an American army general who fought with distinction at the Battle of Bunker Hill during the American Revolutionary War	4,539	518 sq mi (1,342 km2)
Ralls County	173	New London	1821	Pike County	Daniel Ralls, a Missouri State Representative	10,499	471 sq mi (1,220 km2)
Randolph County	175	Huntsville	1829	Chariton and Ralls counties	John Randolph of Roanoke (1773–1833), a leader in Congress from Virginia and spokesman for the "Old Republican"	24,077	482 sq mi (1,248 km2)
Ray County	177	Richmond	1820	Howard County	John Ray, Missouri State Representative	23,199	570 sq mi (1,476 km2)
Reynolds County	179	Centerville	1845	Shannon County	Thomas Reynolds (1796–1844), governor of Missouri from 1840 to 1844	5,927	811 sq mi (2,100 km2)
Ripley County	181	Doniphan	1831	Wayne County	Eleazer Wheelock Ripley (1782–1839), Brigadier General in the War of 1812	10,715	630 sq mi (1,632 km2)
Saint Charles County	183	Saint Charles	1812	One of the five original counties	St. Charles Borromeo (1538–1584), an Italian saint and cardinal of the Roman Catholic Church	423,726	561 sq mi (1,453 km2)
Saint Clair County	185	Osceola	1841	Rives (now Henry) County	Arthur St. Clair (1737–1818), an American soldier and Governor of the Northwest Territory	9,848	677 sq mi (1,753 km2)
Saint Francois County	187	Farmington	1821	Jefferson, Ste. Genevieve and Washington counties	St. Francis of Assisi (c. 1182–1226), a Catholic deacon and the founder of the Order of Friars Minor, more commonly known as the Franciscans	67,503	450 sq mi (1,165 km2)
Saint Louis County	189	Clayton	1812	One of the five original counties	King Louis IX (1214–1270), King of France from 1226 until his death	992,929	508 sq mi (1,316 km2)
Saint Louis City	510	St. Louis	1876	Created in 1876 when city residents voted to secede from St. Louis County	King Louis IX (1214–1270), King of France from 1226 until his death	279,695	61.9 sq mi (160 km2)
Sainte Genevieve County	186	Ste. Genevieve	1812	One of the five original counties	St. Genevieve (c. 420 – c. 510), the patron saint of Paris in Roman Catholic and Eastern Orthodox tradition	18,546	502 sq mi (1,300 km2)
Saline County	195	Marshall	1820	Cooper County	Local hot springs	23,325	756 sq mi (1,958 km2)
Schuyler County	197	Lancaster	1843	Adair County	Philip Schuyler (1733–1804), a general in the American Revolution and a United States Senator from New York	4,069	308 sq mi (798 km2)
Scotland County	199	Memphis	1841	Clark, Lewis, and Shelby counties	Scotland (country)	4,698	438 sq mi (1,134 km2)
Scott County	201	Benton	1822	New Madrid County	John Guier Scott (1819–1892), a U.S. Representative from Missouri	37,957	421 sq mi (1,090 km2)
Shannon County	203	Eminence	1837	Ripley County	George Shannon (1785–1836), member of the Lewis and Clark Expedition	7,275	1,004 sq mi (2,600 km2)
Shelby County	205	Shelbyville	1835	Marion County	Isaac Shelby (1750–1826), the first and fifth Governor of Kentucky	5,926	501 sq mi (1,298 km2)
Stoddard County	207	Bloomfield	1835	New Madrid County	Amos Stoddard (1762–1813), the only commandant of Upper Louisiana for the French Republic and the only commandant for the District of Louisiana for the United States in 1804 during the handover of the Louisiana Purchase	28,438	827 sq mi (2,142 km2)
Stone County	209	Galena	1851	Taney County	William Stone, first elected judge of Taney County	32,630	463 sq mi (1,199 km2)
Sullivan County	211	Milan	1843	Linn County	John Sullivan (1740–1795), American Revolutionary War general	5,750	651 sq mi (1,686 km2)
Taney County	213	Forsyth	1837	Greene County	Roger Brooke Taney (1777–1864), eleventh United States Attorney General and fifth Chief Justice of the United States	56,744	632 sq mi (1,637 km2)
Texas County	215	Houston	1843	Shannon and Wright counties	Republic of Texas	25,715	1,179 sq mi (3,054 km2)
Vernon County	217	Nevada	1851	Bates County	Miles Vernon, Missouri State Senator – the county was originally defined as having the same boundaries as Bates county, but was later declared unconstitutional and changed	19,787	834 sq mi (2,160 km2)
Warren County	219	Warrenton	1833	Montgomery County	Joseph Warren (1741–1775), Revolutionary War doctor and general	38,478	432 sq mi (1,119 km2)
Washington County	221	Potosi	1813	Sainte Genevieve County	George Washington (1732–1799), commander of the Continental Army in the American Revolutionary War and first President of the United States	23,583	760 sq mi (1,968 km2)
Wayne County	223	Greenville	1818	Cape Girardeau and Lawrence counties	Anthony Wayne (1745–1796), United States Army general and statesman	10,820	761 sq mi (1,971 km2)
Webster County	225	Marshfield	1855	Greene County	Daniel Webster (1782–1852), U.S. Secretary of State and Senator from Massachusetts	42,041	593 sq mi (1,536 km2)
Worth County	227	Grant City	1861	Gentry County	William J. Worth (1794–1849), a United States general during the Mexican–American War	1,872	266 sq mi (689 km2)
Wright County	229	Hartville	1841	Pulaski County	Silas Wright (1795–1847), an American Democratic politician and Governor of New York	19,505	682 sq mi (1,766 km2)

Former county names

Former Missouri counties

County[3]	Etymology[3][10]	Changed to[3]
Allen County	Unknown	Atchison County in 1845
Ashley County	William Henry Ashley (1778–1838), early settler	Texas County in 1845 upon organization
Decatur County	Stephen Decatur (1779–1820), American naval officer[13]	Ozark County in 1845
Highland County	Unknown	Sullivan County in 1845 upon organization
Kinderhook County	Kinderhook, New York, birthplace of Martin Van Buren	Camden County in 1843
Lillard County	James Lillard of Tennessee, who served in the first state legislature of Missouri	Lafayette County in 1825
Niangua County	Niangua River, a tributary of the Osage River – "niangua" comes from the Native American word nehemgar, which means "a river of numerous springs or sources"[14]	Dallas County in 1844 because of the difficulty in pronouncing and spelling Niangua
Seneca County	Seneca Nation, a group of Native Americans from New York	McDonald County in 1847 upon organization
Van Buren County	Martin Van Buren (1782–1862), eighth President of the United States and also Vice President under Andrew Jackson	Cass County in 1849 in honor of Van Buren's opponent in the presidential election of 1848

See also

• List of municipalities in Missouri
• List of U.S. counties by population
• Missouri census statistical areas
• Demographics of Missouri