Largest Counties in Kansas

Known for the “Bleeding Kansas” conflict over slavery before the Civil War, Kansas became a state in 1861. It is part of America’s breadbasket, known for wheat production. Kansas has 105 counties.

10 Largest Counties in Kansas

1. Johnson County

County Facts:

  • Population: Approximately 620,000
  • Area Codes: 913
  • Zip Codes: 66006, 66030, 66201–66227, 66250, 66251, 66276, 66282, 66283
  • County Seat: Olathe

Geography and History:

Johnson County is located in northeastern Kansas and covers 477 square miles. The county is part of the Kansas City metropolitan area and features a mix of suburban developments, rolling hills, and rivers, including the Kansas and Blue Rivers. The climate is humid continental, with hot summers and cold winters.

Founded in 1855, Johnson County was named after Reverend Thomas Johnson, a Methodist missionary who established the Shawnee Methodist Mission in the region. The county grew rapidly as a result of its proximity to Kansas City and became a major suburban and commercial hub. Today, it is one of the wealthiest and most populous counties in Kansas, known for its high quality of life, excellent schools, and thriving business community.

Colleges and Universities:

  • Johnson County Community College (JCCC): One of the largest community colleges in the state, offering associate degrees, certifications, and continuing education programs in a variety of fields.
  • MidAmerica Nazarene University: A private Christian university located in Olathe, offering undergraduate and graduate programs in nursing, business, education, and ministry.
  • University of Kansas (Edwards Campus): Offers graduate and professional programs in areas like engineering, business, and public administration for students in the Kansas City area.
  • Cleveland University-Kansas City: A private university specializing in chiropractic education and health sciences.

Major Landmarks:

Johnson County is home to the Shawnee Indian Mission State Historic Site, which highlights the early history of Native Americans and missionaries in Kansas. The Overland Park Arboretum and Botanical Gardens offers beautiful landscapes and walking trails. Deanna Rose Children’s Farmstead is a popular family destination that showcases farm life in Kansas. The Nerman Museum of Contemporary Art, located at JCCC, features modern art exhibitions and local artists.


2. Sedgwick County

County Facts:

  • Population: Approximately 523,000
  • Area Codes: 316
  • Zip Codes: 67001–67278
  • County Seat: Wichita

Geography and History:

Sedgwick County is located in south-central Kansas, covering 1,009 square miles. The county is part of the Great Plains, featuring flat agricultural land and the Arkansas River running through Wichita, the county’s largest city. The climate is characterized by hot summers and cold winters, with occasional tornadoes.

Sedgwick County was founded in 1867 and named after Major General John Sedgwick, a Union Army officer during the Civil War. Wichita grew as a trading post and cattle town in the 1870s, eventually becoming a major manufacturing and aviation hub. The city earned the nickname “Air Capital of the World” due to its significant role in the aerospace industry. Today, Sedgwick County is the economic center of Kansas, driven by industries such as aviation, healthcare, and manufacturing.

Colleges and Universities:

  • Wichita State University (WSU): A large public research university offering undergraduate, graduate, and doctoral programs in fields such as engineering, business, health sciences, and the arts.
  • Friends University: A private Christian university offering programs in education, business, and the sciences, with a strong focus on adult and graduate education.
  • Newman University: A private Catholic university in Wichita, known for its programs in nursing, education, and business.
  • Butler Community College (Andover Campus): Offers associate degrees, technical certifications, and continuing education to residents of the Wichita area.

Major Landmarks:

Wichita’s Botanica Gardens is a major attraction, featuring themed gardens and seasonal events. Sedgwick County Zoo, one of the largest zoos in the U.S., is a popular destination for families. The Keeper of the Plains, a 44-foot statue along the Arkansas River, is a significant cultural landmark. Old Cowtown Museum offers a glimpse into Wichita’s Wild West past, while the Kansas Aviation Museum celebrates the city’s role in the aviation industry.


3. Shawnee County

County Facts:

  • Population: Approximately 178,000
  • Area Codes: 785
  • Zip Codes: 66409, 66414, 66429, 66440, 66501, 66507, 66601–66699
  • County Seat: Topeka

Geography and History:

Shawnee County is located in northeastern Kansas and spans 556 square miles. The Kansas River flows through the county, and the terrain consists of rolling plains and farmland. The climate is typical of the Midwest, with hot summers, cold winters, and moderate precipitation.

Established in 1855, Shawnee County was named after the Shawnee Native American tribe. Topeka, the county seat and the capital of Kansas, played a significant role in the fight for racial equality, being home to the historic Brown v. Board of Education case that led to the desegregation of U.S. public schools. Topeka grew rapidly in the 19th century as a railroad and industrial center, becoming a hub for government, manufacturing, and agriculture.

Colleges and Universities:

  • Washburn University: A public university in Topeka offering a range of undergraduate and graduate programs in law, business, nursing, and the liberal arts.
  • Washburn Institute of Technology: A technical and vocational institution affiliated with Washburn University, providing workforce training and certification programs.
  • Baker University (Topeka Campus): A satellite campus of the private Christian university, offering graduate programs in education and business for working adults.
  • Bryan University (Topeka Campus): Provides career-oriented programs in healthcare, business, and information technology.

Major Landmarks:

The Kansas State Capitol in Topeka is a major landmark, featuring stunning murals and offering guided tours. The Brown v. Board of Education National Historic Site commemorates the landmark Supreme Court case that ended school segregation. Gage Park, home to the Topeka Zoo and the Kansas Children’s Discovery Center, is a popular family destination. Lake Shawnee offers recreational opportunities, including boating, fishing, and walking trails. The Combat Air Museum showcases military aviation history and aircraft.


4. Wyandotte County

County Facts:

  • Population: Approximately 165,000
  • Area Codes: 913
  • Zip Codes: 66101–66160
  • County Seat: Kansas City

Geography and History:

Wyandotte County, located in northeastern Kansas, covers 156 square miles and is part of the Kansas City metropolitan area. The county’s geography is dominated by the confluence of the Kansas and Missouri Rivers, with flat plains and suburban developments. The climate is humid continental, with hot summers and cold winters.

Established in 1859, Wyandotte County was named after the Wyandot Native American tribe, which originally inhabited the area. Kansas City, Kansas (KCK), serves as the county seat and is one of the most densely populated urban centers in Kansas. The county has a rich industrial history and was historically an important hub for railroads, manufacturing, and agriculture. In 1997, the city of Kansas City and Wyandotte County consolidated their governments, creating the Unified Government of Wyandotte County.

Colleges and Universities:

  • Kansas City Kansas Community College (KCKCC): A public community college offering associate degrees, certificates, and workforce development programs to students in Wyandotte County.
  • Donnelly College: A private Catholic institution in Kansas City, offering associate and bachelor’s degrees, particularly known for its commitment to serving underrepresented populations.
  • University of Kansas Medical Center: Located in Kansas City, Kansas, it offers programs in medicine, nursing, and allied health, and is affiliated with the University of Kansas.
  • Park University (Kansas City Campus): Offers undergraduate and graduate programs in business, education, and public administration.

Major Landmarks:

The Kansas Speedway is a major landmark, hosting NASCAR and other racing events. Legends Outlets Kansas City is a popular shopping and entertainment district, while Children’s Mercy Park is home to the Major League Soccer team Sporting Kansas City. The Schlitterbahn Waterpark is a seasonal attraction, offering thrilling water rides. The Strawberry Hill Museum and Cultural Center showcases the rich Eastern European heritage of the area.


5. Douglas County

County Facts:

  • Population: Approximately 121,000
  • Area Codes: 785
  • Zip Codes: 66006, 66044, 66045, 66046, 66047, 66049, 66050
  • County Seat: Lawrence

Geography and History:

Douglas County is located in northeastern Kansas and covers 475 square miles. The Kansas River flows through Lawrence, the county seat, and the region features rolling plains, farmland, and wooded areas. The climate is characterized by hot summers, cold winters, and moderate rainfall.

Douglas County was established in 1854 and played a critical role in the “Bleeding Kansas” conflict, as pro-slavery and anti-slavery settlers clashed over whether Kansas would be a free or slave state. Lawrence, founded by abolitionists, became a center of anti-slavery activism. The county’s history is also tied to the founding of the University of Kansas in Lawrence in 1865, which shaped the county’s development as a hub for education, arts, and culture.

Colleges and Universities:

  • University of Kansas (KU): The flagship public research university of Kansas, known for its programs in law, engineering, business, and the liberal arts. It is also home to the KU Jayhawks sports teams.
  • Haskell Indian Nations University: A federally operated tribal university in Lawrence, offering undergraduate programs for Native American students across the U.S.
  • Baker University (Baldwin City Campus): The oldest university in Kansas, offering undergraduate and graduate programs in business, education, and the arts.
  • Johnson County Community College (Lawrence Campus): Offers associate degrees and technical programs to residents of Douglas County.

Major Landmarks:

The University of Kansas’ Spencer Museum of Art and Allen Fieldhouse, the home of KU basketball, are major landmarks. Clinton Lake, located just outside Lawrence, offers boating, fishing, and camping. Massachusetts Street, known as “Mass Street,” is the cultural heart of Lawrence, featuring shops, restaurants, and historic architecture. The Wakarusa River Valley Heritage Museum highlights the area’s Civil War-era history. The Haskell Cultural Center and Museum offers insights into Native American heritage.


6. Riley County

County Facts:

  • Population: Approximately 75,000
  • Area Codes: 785
  • Zip Codes: 66502–66506
  • County Seat: Manhattan

Geography and History:

Riley County is located in northeastern Kansas, covering 622 square miles. The geography includes the Flint Hills, a region of rolling hills and tallgrass prairies. The county is bisected by the Kansas and Big Blue Rivers, providing scenic views and fertile farmland. The climate is continental, with cold winters and hot summers.

Riley County was established in 1855 and named after Mexican-American War hero General Bennet Riley. The county seat, Manhattan, is often called the “Little Apple” and serves as the home of Kansas State University. Riley County’s history is tied to the growth of education and agriculture, with K-State playing a key role in the county’s development since its founding in 1863. Fort Riley, a major U.S. Army installation, is also partially located in Riley County.

Colleges and Universities:

  • Kansas State University (K-State): A major public research university offering a wide range of programs, including agriculture, engineering, business, and veterinary medicine. K-State is known for its research contributions in agriculture and biosecurity.
  • Manhattan Area Technical College (MATC): Provides technical and vocational education in fields such as healthcare, engineering technology, and industrial trades.
  • American Institute of Baking (AIB): An internationally recognized institute in Manhattan that offers education and training in baking technology and food safety.

Major Landmarks:

Konza Prairie Biological Station, located south of Manhattan, is a key landmark and research site dedicated to studying the tallgrass prairie ecosystem. Tuttle Creek Lake offers recreational activities, including boating, fishing, and camping. The Flint Hills Discovery Center in Manhattan provides an interactive look at the region’s natural and cultural history. Fort Riley, home of the 1st Infantry Division (the “Big Red One”), offers historical tours and military exhibits.


7. Leavenworth County

County Facts:

  • Population: Approximately 82,000
  • Area Codes: 913
  • Zip Codes: 66007, 66027, 66043, 66048, 66086
  • County Seat: Leavenworth

Geography and History:

Leavenworth County is located in northeastern Kansas and covers 469 square miles. The county is characterized by its rolling plains, wooded areas, and proximity to the Missouri River, which forms its eastern border. The climate is typical of the Midwest, with four distinct seasons.

Leavenworth County was one of the first counties established in Kansas in 1855, and the city of Leavenworth, founded in 1854, became the first city in the state. It played an important role in the westward expansion of the U.S., serving as a key outpost on the Missouri River. The area is also known for Fort Leavenworth, a historic military installation that has been in continuous operation since 1827 and is home to the U.S. Army’s Command and General Staff College.

Colleges and Universities:

  • University of Saint Mary: A private Catholic university located in Leavenworth, offering undergraduate and graduate programs in business, healthcare, education, and the liberal arts.
  • Kansas City Kansas Community College (Leavenworth Campus): Offers associate degrees, certificates, and continuing education programs in fields such as nursing, business, and criminal justice.
  • Fort Leavenworth’s Command and General Staff College: A U.S. Army institution that trains military officers in leadership, strategy, and national security.

Major Landmarks:

Fort Leavenworth, one of the oldest military installations in the U.S., is a major landmark and includes the Frontier Army Museum, which highlights the history of the U.S. Army in the West. The Leavenworth National Cemetery is a historic resting place for veterans. C.W. Parker Carousel Museum in Leavenworth preserves the art of carousel building and offers rides on restored carousels. The Richard Allen Cultural Center showcases the history of African Americans in the region.


8. Butler County

County Facts:

  • Population: Approximately 67,000
  • Area Codes: 316
  • Zip Codes: 67002–67155
  • County Seat: El Dorado

Geography and History:

Butler County is located in south-central Kansas and covers 1,428 square miles, making it the largest county in the state by land area. The county features rolling prairies, farmland, and the Flint Hills region, which provides scenic landscapes and tallgrass prairie. The climate is continental, with hot summers and cold winters.

Established in 1855, Butler County was named after Andrew Butler, a U.S. Senator from South Carolina. El Dorado, the county seat, grew rapidly with the discovery of oil in the early 20th century, leading to an oil boom that shaped the region’s economy for decades. Today, agriculture, energy production, and education are key industries in Butler County.

Colleges and Universities:

  • Butler Community College (BCC): One of the largest community colleges in Kansas, offering associate degrees, certificates, and workforce training in fields such as nursing, agriculture, and information technology.
  • Wichita State University (WSU – Butler Campus): Offers degree programs and continuing education in partnership with Butler Community College, providing expanded educational opportunities for students in the region.
  • Emporia State University (El Dorado Campus): Provides undergraduate and graduate programs in education, business, and the arts through its El Dorado satellite campus.

Major Landmarks:

El Dorado State Park is one of the largest state parks in Kansas, offering camping, fishing, and boating on El Dorado Lake. The Kansas Oil Museum in El Dorado explores the county’s rich history in oil production and the impact of the oil boom. The Flinthills Overlook provides scenic views of the Flint Hills region, while Butler County History Center and Kansas Oil Museum in El Dorado preserves the region’s history in energy and agriculture.


9. Geary County

County Facts:

  • Population: Approximately 36,000
  • Area Codes: 785
  • Zip Codes: 66441, 66442
  • County Seat: Junction City

Geography and History:

Geary County is located in northeastern Kansas and covers 404 square miles. The county is home to Milford Lake, the largest man-made lake in Kansas, and is part of the Flint Hills region, with rolling hills, forests, and prairies. The climate is characterized by hot summers and cold winters.

Established in 1855, Geary County was originally called Davis County but was renamed in 1889 in honor of John W. Geary, a governor of the Kansas Territory. The county seat, Junction City, developed as a key military town due to its proximity to Fort Riley, a major U.S. Army installation that has played a significant role in the defense of the U.S. since the 19th century.

Colleges and Universities:

  • Cloud County Community College (Geary Campus): Offers associate degrees and vocational programs for students in Geary County and the surrounding region.
  • Kansas State University (KSU): Located nearby in Manhattan, many residents of Geary County attend KSU for undergraduate and graduate programs in business, engineering, and agriculture.
  • Fort Riley’s Command and General Staff College: Provides advanced education for U.S. military officers, specializing in leadership, national security, and defense strategy.

Major Landmarks:

Milford Lake is a key landmark, offering boating, fishing, and wildlife viewing in the Milford Nature Center. Fort Riley, a historic U.S. Army post, is home to the 1st Infantry Division Museum and provides visitors with a look into military history. Heritage Park in Junction City honors the city’s military heritage, while Geary State Fishing Lake offers outdoor recreation. The Custer House at Fort Riley preserves 19th-century military life.


10. Finney County

County Facts:

  • Population: Approximately 38,000
  • Area Codes: 620
  • Zip Codes: 67801–67868
  • County Seat: Garden City

Geography and History:

Finney County is located in southwestern Kansas and covers 1,302 square miles. The geography includes flat prairies and farmland, with a semi-arid climate characterized by hot summers and cold winters. Agriculture, especially cattle ranching and crop farming, plays a central role in the local economy.

Finney County was established in 1883, named after Kansas Lieutenant Governor David W. Finney. Garden City, the county seat, grew as a key agricultural hub, particularly with the advent of irrigation and the development of large-scale farming. Today, Finney County remains an important center for agriculture, with meatpacking and food processing driving much of the local economy.

Colleges and Universities:

  • Garden City Community College (GCCC): Provides associate degrees, technical certifications, and workforce training for the residents of Finney County and the surrounding region.
  • Kansas State University (Garden City Research Extension): Supports agricultural research and development in western Kansas, offering programs to improve crop yields and farming techniques.
  • Fort Hays State University (Garden City Campus): Offers distance learning and in-person programs through a partnership with Garden City Community College, providing expanded opportunities for higher education in the region.

Major Landmarks:

Lee Richardson Zoo in Garden City is one of the oldest zoos in Kansas and a popular destination for families. The Finney County Historical Museum preserves the history of the region’s agricultural and pioneer heritage. Buffalo Dunes Golf Course is a highly regarded public course located in Garden City. The Sandsage Bison Range and Wildlife Area offers a chance to see bison and other native wildlife in their natural habitat.