There are a total of 114 counties in the state of Missouri. Among them, Cape Girardeau County is the oldest one (established in 1812) while Saint Louis City is the youngest (established in 1876). With population of 1,000,438, Saint Louis County is the most populated. The biggest county by land area is Texas County (3,054 km2) and the smallest is Saint Louis City (160 km2). Below please see all Missouri counties which are listed in alphabetical order.
- Adair County, MO
- Andrew County, MO
- Atchison County, MO
- Audrain County, MO
- Barry County, MO
- Barton County, MO
- Bates County, MO
- Benton County, MO
- Bollinger County, MO
- Boone County, MO
- Buchanan County, MO
- Butler County, MO
- Caldwell County, MO
- Callaway County, MO
- Camden County, MO
- Cape Girardeau County, MO
- Carroll County, MO
- Carter County, MO
- Cass County, MO
- Cedar County, MO
- Chariton County, MO
- Christian County, MO
- Clark County, MO
- Clay County, MO
- Clinton County, MO
- Cole County, MO
- Cooper County, MO
- Crawford County, MO
- Dade County, MO
- Dallas County, MO
- Daviess County, MO
- DeKalb County, MO
- Dent County, MO
- Douglas County, MO
- Dunklin County, MO
- Franklin County, MO
- Gasconade County, MO
- Gentry County, MO
- Greene County, MO
- Grundy County, MO
- Harrison County, MO
- Henry County, MO
- Hickory County, MO
- Holt County, MO
- Howard County, MO
- Howell County, MO
- Iron County, MO
- Jackson County, MO
- Jasper County, MO
- Jefferson County, MO
- Johnson County, MO
- Knox County, MO
- Laclede County, MO
- Lafayette County, MO
- Lawrence County, MO
- Lewis County, MO
- Lincoln County, MO
- Linn County, MO
- Livingston County, MO
- Macon County, MO
- Madison County, MO
- Maries County, MO
- Marion County, MO
- McDonald County, MO
- Mercer County, MO
- Miller County, MO
- Mississippi County, MO
- Moniteau County, MO
- Monroe County, MO
- Montgomery County, MO
- Morgan County, MO
- New Madrid County, MO
- Newton County, MO
- Nodaway County, MO
- Oregon County, MO
- Osage County, MO
- Ozark County, MO
- Pemiscot County, MO
- Perry County, MO
- Pettis County, MO
- Phelps County, MO
- Pike County, MO
- Platte County, MO
- Polk County, MO
- Pulaski County, MO
- Putnam County, MO
- Ralls County, MO
- Randolph County, MO
- Ray County, MO
- Reynolds County, MO
- Ripley County, MO
- Saint Charles County, MO
- Saint Clair County, MO
- Saint Francois County, MO
- Saint Louis County, MO
- Sainte Genevieve County, MO
- Saline County, MO
- Schuyler County, MO
- Scotland County, MO
- Scott County, MO
- Shannon County, MO
- Shelby County, MO
- Stoddard County, MO
- Stone County, MO
- Sullivan County, MO
- Taney County, MO
- Texas County, MO
- Vernon County, MO
- Warren County, MO
- Washington County, MO
- Wayne County, MO
- Webster County, MO
- Worth County, MO
- Wright County, MO