Admitted as part of the Missouri Compromise in 1821, Missouri was a border state during the Civil War and has a history tied to westward expansion. Missouri has 114 counties and 1 independent city (St. Louis).
10 Largest Counties in Missouri
1. St. Louis County
County Facts:
- Population: Approximately 1 million
- Area Codes: 314, 636
- Zip Codes: 63005–63199
- County Seat: Clayton
Geography and History:
St. Louis County is located in eastern Missouri, covering 523 square miles, with the Missouri River to the north and the Mississippi River to the east. The county is part of the Greater St. Louis metropolitan area, featuring suburban developments, wooded hills, and rivers. It experiences a humid continental climate with hot summers and cold winters.
Founded in 1812, St. Louis County is separate from the city of St. Louis, which became an independent city in 1877. The county’s growth surged in the mid-20th century as suburban development expanded from St. Louis. Today, St. Louis County is one of the most populous and economically important regions in Missouri, known for its diverse industries, including healthcare, finance, and education.
Colleges and Universities:
- Washington University in St. Louis: A prestigious private university known for its programs in law, business, medicine, and engineering.
- University of Missouri–St. Louis (UMSL): A public university offering undergraduate, graduate, and doctoral programs in fields like business, education, and science.
- Maryville University: A private university offering degrees in nursing, business, and technology, known for its online education programs.
- St. Louis Community College: Offers associate degrees and certificates in various fields such as healthcare, technology, and business, with multiple campuses across the county.
Major Landmarks:
St. Louis County is home to the Missouri History Museum, which offers exhibits on the region’s history. Forest Park is one of the largest urban parks in the U.S., featuring the Saint Louis Zoo, Saint Louis Art Museum, and The Muny outdoor theater. Grant’s Farm, the former estate of Ulysses S. Grant, is a popular family destination. The Laumeier Sculpture Park offers modern art installations in a natural setting. Creve Coeur Lake Memorial Park is another popular spot for outdoor recreation.
2. Jackson County
County Facts:
- Population: Approximately 720,000
- Area Codes: 816, 913
- Zip Codes: 64002–64199
- County Seat: Kansas City and Independence (dual seats)
Geography and History:
Jackson County is located in western Missouri, covering 616 square miles. The county includes the urban areas of Kansas City and Independence, as well as suburban and rural areas. The Missouri River runs along the county’s northern border. The climate is humid continental, with hot summers and cold winters.
Founded in 1826, Jackson County was named after President Andrew Jackson. Kansas City grew as a significant center for trade, cattle, and transportation, particularly due to its location on the Missouri River and its role in the Santa Fe Trail. Independence was an important starting point for westward expansion and the Oregon Trail. Today, Jackson County remains a major cultural and economic center in Missouri, with a strong focus on transportation, healthcare, and technology.
Colleges and Universities:
- University of Missouri–Kansas City (UMKC): A public research university offering programs in law, medicine, business, and the arts.
- Rockhurst University: A private Jesuit university known for its strong programs in business, education, and health sciences.
- Metropolitan Community College (Kansas City): Offers associate degrees and vocational training in fields such as healthcare, technology, and business.
- Avila University: A private Catholic university offering degrees in education, business, nursing, and the liberal arts.
Major Landmarks:
Jackson County is home to the National World War I Museum and Memorial, located in Kansas City, which offers exhibits on the history of World War I. Union Station is a historic train station that now houses museums, restaurants, and an aquarium. Kauffman Stadium and Arrowhead Stadium are home to the Kansas City Royals (MLB) and Kansas City Chiefs (NFL), respectively. Harry S. Truman Presidential Library and Museum in Independence showcases the life and legacy of the 33rd U.S. president. The Nelson-Atkins Museum of Art offers an extensive collection of art from around the world.
3. St. Charles County
County Facts:
- Population: Approximately 410,000
- Area Codes: 636
- Zip Codes: 63301–63385
- County Seat: St. Charles
Geography and History:
St. Charles County is located in eastern Missouri, covering 593 square miles. It lies west of St. Louis County and is part of the Greater St. Louis metropolitan area. The Missouri River runs through the county, contributing to its scenic beauty. The terrain includes a mix of urban, suburban, and rural areas. The climate is similar to the rest of eastern Missouri, with hot summers and cold winters.
Founded in 1812, St. Charles County has a rich history as the original state capital of Missouri from 1821 to 1826. The area was a key stop for explorers Lewis and Clark as they began their journey westward. The county saw significant growth in the 20th century as suburban development expanded from St. Louis, making it one of the fastest-growing counties in the state today.
Colleges and Universities:
- Lindenwood University: A private university in St. Charles, offering a wide range of undergraduate and graduate programs, particularly strong in education, business, and the arts.
- St. Charles Community College: Provides associate degrees and certifications in fields like healthcare, business, and information technology.
- Maryville University (Dardenne Prairie Campus): Offers degree completion programs, online education, and graduate degrees for working professionals in the region.
- Missouri Baptist University (St. Charles Campus): Provides undergraduate and graduate programs in education, business, and the liberal arts.
Major Landmarks:
St. Charles County is home to Historic Main Street in downtown St. Charles, where visitors can explore shops, restaurants, and buildings dating back to the 19th century. The Lewis and Clark Boathouse and Nature Center celebrates the famous expedition. Katy Trail State Park, the longest rail-trail conversion in the U.S., offers biking and hiking along the Missouri River. Augusta Wine Region, located in the county, is known for its vineyards and scenic views. The Family Arena hosts sporting events, concerts, and exhibitions throughout the year.
4. Greene County
County Facts:
- Population: Approximately 300,000
- Area Codes: 417
- Zip Codes: 65604–65899
- County Seat: Springfield
Geography and History:
Greene County is located in southwestern Missouri and covers 678 square miles. The county features a mix of urban, suburban, and rural areas, with Springfield, the third-largest city in Missouri, serving as the county seat. The geography includes rolling hills, forests, and rivers, with a humid continental climate characterized by cold winters and hot summers.
Founded in 1833, Greene County was named after Nathanael Greene, a general in the American Revolutionary War. Springfield grew as a key trading post along the Butterfield Overland Mail route and played a significant role in the American Civil War. The region became known as a hub for education and healthcare, with significant growth in the 20th century due to its strategic location and strong economic base.
Colleges and Universities:
- Missouri State University (MSU): A large public university offering programs in business, health sciences, education, and the arts, known for its strong emphasis on public affairs and leadership.
- Drury University: A private liberal arts college known for its programs in architecture, business, and the sciences.
- Ozarks Technical Community College (OTC): Offers associate degrees, certifications, and technical training in fields like automotive technology, healthcare, and business.
- Evangel University: A private Christian university offering undergraduate and graduate programs in theology, education, and the liberal arts.
Major Landmarks:
Greene County is home to Fantastic Caverns, a ride-through cave attraction showcasing stunning rock formations. Wilson’s Creek National Battlefield commemorates one of the first major battles of the Civil War. Bass Pro Shops Outdoor World in Springfield is a massive retail and entertainment complex, featuring an aquarium, museum, and wildlife exhibits. The Springfield Art Museum offers rotating exhibits of modern and contemporary art. Route 66 Car Museum highlights classic cars and the history of the famous highway.
5. Clay County
County Facts:
- Population: Approximately 260,000
- Area Codes: 816
- Zip Codes: 64024–64158
- County Seat: Liberty
Geography and History:
Clay County is located in western Missouri, covering 409 square miles, and is part of the Kansas City metropolitan area. The geography includes rolling hills, rivers, and suburban developments. The Missouri River forms the county’s northern boundary. The climate is typical of the Midwest, with cold winters and hot, humid summers.
Founded in 1822, Clay County was named after Henry Clay, a prominent American statesman. The county grew rapidly in the 19th century as settlers moved westward, and it played a role in the Civil War due to its location near Kansas. Liberty, the county seat, was the site of the first daytime bank robbery in U.S. history, attributed to Jesse James. Today, Clay County is known for its suburban communities and proximity to Kansas City.
Colleges and Universities:
- William Jewell College: A private liberal arts college in Liberty, offering strong programs in business, education, and the sciences.
- Metropolitan Community College (Maple Woods Campus): Provides associate degrees and technical certifications in fields such as healthcare, business, and education.
- Park University: Located nearby in Platte County, but serving many Clay County residents, Park offers programs in business, public administration, and information technology.
- University of Missouri–Kansas City (UMKC): Many students from Clay County attend UMKC for undergraduate and graduate programs in law, medicine, engineering, and business.
Major Landmarks:
Clay County is home to Jesse James Bank Museum in Liberty, which commemorates the infamous bank robbery. Liberty Jail Historic Site offers insights into the early history of the Latter-day Saints Church and its founder, Joseph Smith. Smithville Lake provides opportunities for boating, fishing, and camping. Shoal Creek Living History Museum features historic buildings and reenactments of 19th-century life. Worlds of Fun amusement park, located just outside the county, is a major family destination.
6. Jefferson County
County Facts:
- Population: Approximately 225,000
- Area Codes: 636
- Zip Codes: 63010–65584
- County Seat: Hillsboro
Geography and History:
Jefferson County is located in eastern Missouri, covering 664 square miles. The county is part of the St. Louis metropolitan area, with the Mississippi River forming its eastern border. The geography includes rolling hills, forests, and rivers. The climate is similar to the rest of eastern Missouri, with hot summers and cold winters.
Founded in 1818, Jefferson County was named after Thomas Jefferson, the third president of the United States. The county grew as a center for agriculture, mining, and transportation, thanks to its location along the Mississippi River. Over time, Jefferson County developed into a suburban area, with many residents commuting to St. Louis for work.
Colleges and Universities:
- Jefferson College: A public community college offering associate degrees and certificates in healthcare, business, and technology.
- Missouri Baptist University (Jefferson County Regional Learning Center): Provides degree completion programs and professional development courses in education, business, and healthcare.
- University of Missouri–St. Louis (UMSL): While located in nearby St. Louis County, UMSL serves many students from Jefferson County with programs in business, education, and science.
- Lindenwood University: Many residents of Jefferson County attend Lindenwood for undergraduate and graduate programs in business, education, and healthcare.
Major Landmarks:
Jefferson County is home to Sandy Creek Covered Bridge, one of the last remaining covered bridges in Missouri. Mastodon State Historic Site preserves fossils of prehistoric creatures and offers hiking trails and a museum. Big River and Meramec River offer opportunities for boating, fishing, and camping. LaBarque Creek Conservation Area features scenic views, hiking, and birdwatching. Fort de Chartres, located just across the Mississippi River in Illinois, offers insights into the region’s colonial history.
7. Boone County
County Facts:
- Population: Approximately 185,000
- Area Codes: 573
- Zip Codes: 65001–65299
- County Seat: Columbia
Geography and History:
Boone County is located in central Missouri, covering 690 square miles. The county is primarily rural, with Columbia, the largest city, serving as the urban center. The geography includes rolling hills, rivers, and farmland, with the Missouri River forming part of its southern boundary. The climate is continental, with cold winters and hot summers.
Founded in 1820, Boone County was named after the famous frontiersman Daniel Boone. Columbia grew as an educational and cultural hub, largely due to the establishment of the University of Missouri in 1839. The county’s economy has diversified over time, with healthcare, education, and agriculture playing significant roles. Boone County is one of the fastest-growing counties in Missouri due to its central location and vibrant economy.
Colleges and Universities:
- University of Missouri (Mizzou): The flagship public university in Missouri, offering a wide range of undergraduate, graduate, and doctoral programs in fields such as business, journalism, engineering, and medicine.
- Columbia College: A private liberal arts college known for its strong online and evening programs for working adults.
- Stephens College: A private women’s college offering programs in the arts, business, and healthcare.
- Moberly Area Community College (Columbia Campus): Offers associate degrees and certificates in business, healthcare, and technology for students in Boone County.
Major Landmarks:
Boone County is home to the University of Missouri’s Francis Quadrangle, a historic area of campus featuring the famous columns of the old Academic Hall. Rock Bridge Memorial State Park offers hiking, cave exploration, and scenic views. The District in downtown Columbia features shops, restaurants, and entertainment venues, making it a popular destination for residents and students alike. Shelter Gardens offers beautifully landscaped gardens and a walking trail. Finger Lakes State Park is a popular spot for off-roading, boating, and fishing.
8. Franklin County
County Facts:
- Population: Approximately 105,000
- Area Codes: 636, 573
- Zip Codes: 63013–65441
- County Seat: Union
Geography and History:
Franklin County is located in east-central Missouri, covering 923 square miles. The geography features rolling hills, forests, and rivers, with the Missouri River forming its northern boundary. The county includes both rural and suburban areas. The climate is similar to other parts of Missouri, with hot summers and cold winters.
Founded in 1818, Franklin County was named after Benjamin Franklin. The county’s history is closely tied to agriculture, mining, and the river trade. As part of the Missouri Rhineland, Franklin County also has a strong tradition of winemaking. In recent decades, suburban growth from St. Louis has spread into the county, making it a mix of rural and suburban lifestyles.
Colleges and Universities:
- East Central College: A public community college offering associate degrees and certificates in fields such as healthcare, business, and industrial technology.
- Missouri Baptist University (Union Campus): Offers degree completion programs and professional development courses in business, education, and healthcare for residents of Franklin County.
- University of Missouri–St. Louis (UMSL): Though based in St. Louis, UMSL serves Franklin County students, offering a variety of undergraduate and graduate programs.
- Lindenwood University (St. Charles): Franklin County residents often attend nearby Lindenwood University for programs in education, business, and health sciences.
Major Landmarks:
Franklin County is home to Meramec Caverns, a popular tourist attraction featuring stunning underground formations. Missouri’s Wine Country in the Augusta and Hermann regions offers scenic vineyards and wineries. Shaw Nature Reserve, located in Gray Summit, provides walking trails and opportunities to explore Missouri’s natural landscapes. Robertsville State Park offers camping, hiking, and fishing along the Meramec River. Washington, Missouri, known as the “Corncob Pipe Capital of the World,” celebrates its heritage with a charming downtown area and annual festivals.
9. Platte County
County Facts:
- Population: Approximately 105,000
- Area Codes: 816
- Zip Codes: 64018–64179
- County Seat: Platte City
Geography and History:
Platte County is located in northwestern Missouri, covering 427 square miles. The Missouri River forms the county’s western and northern borders. The geography features rolling hills, rivers, and suburban developments. The climate is similar to the rest of western Missouri, with cold winters and hot, humid summers.
Founded in 1838, Platte County was named after the Platte River. The county grew as a center for agriculture, but over time, its proximity to Kansas City led to suburban development. Today, Platte County is known for its mix of rural landscapes and growing suburban communities, particularly around Parkville and Kansas City International Airport.
Colleges and Universities:
- Park University: A private university in Parkville offering undergraduate and graduate programs in business, public administration, and education.
- Metropolitan Community College (Platte County Campus): Offers associate degrees and certificates in fields like healthcare, business, and information technology.
- University of Missouri–Kansas City (UMKC): Many residents of Platte County attend UMKC for undergraduate and graduate programs in law, medicine, and the arts.
- Rockhurst University: Nearby in Kansas City, Rockhurst offers strong programs in business, nursing, and physical therapy for Platte County residents.
Major Landmarks:
Platte County is home to Parkville’s Historic Downtown, featuring charming shops, restaurants, and scenic views of the Missouri River. Weston Bend State Park offers hiking trails, camping, and views of the Missouri River. Kansas City International Airport is a major transportation hub for the region. The National Golf Club of Kansas City in Parkville is a prestigious golf course and country club. Snow Creek Ski Resort, located near Weston, offers winter sports such as skiing and snowboarding.
10. Buchanan County
County Facts:
- Population: Approximately 88,000
- Area Codes: 816
- Zip Codes: 64401–64508
- County Seat: St. Joseph
Geography and History:
Buchanan County is located in northwestern Missouri, covering 415 square miles. The county’s geography includes rivers, rolling hills, and farmland, with the Missouri River forming part of its western boundary. The climate is typical of the Midwest, with hot summers and cold winters.
Founded in 1838, Buchanan County was named after James Buchanan, who later became the 15th president of the United States. St. Joseph grew as a key trading post along the Missouri River and became famous as the starting point of the Pony Express. The county also played a role in the westward expansion of the United States. Today, Buchanan County is known for its agricultural base and historical significance.
Colleges and Universities:
- Missouri Western State University: A public university offering undergraduate and graduate programs in business, nursing, education, and the arts, known for its strong emphasis on applied learning.
- Highland Community College (Wathena, Kansas Campus): Offers associate degrees and vocational training, with many Buchanan County residents attending for its proximity.
- Northwest Missouri State University: Located nearby, many students from Buchanan County attend this university for programs in business, education, and agriculture.
- Hillyard Technical Center: Provides technical and vocational training in fields like healthcare, industrial technology, and automotive technology.
Major Landmarks:
Buchanan County is home to the Pony Express National Museum, which celebrates the history of the famous mail service. Jesse James Home Museum in St. Joseph commemorates the life and death of the infamous outlaw. Krug Park offers scenic views, walking trails, and a historic Italian-style castle. Mount Mora Cemetery is the resting place of many prominent figures from the region’s history. Missouri Theater is a historic venue in downtown St. Joseph that hosts concerts, plays, and community events.