Top 10 Most Populated Counties in Missouri

Here are the 10 most populated counties in Missouri (along with the next 10 for good measure!) according to the 2022 Census Population Estimates. St. Louis County’s population continues to fall. It is once again below 1,000,000 residents after holding at or above that level for several years. Meanwhile, Jackson County continues to grow rapidly on the western side of the state. The outer ring suburbs around the major cities of the state also continue to see massive growth as Missourians move further away from the “city centers.”

Rank County Population

1. St. Louis County 990,414
2. Jackson County 716,531
3. St. Charles County 413,803
4. Greene County 303,293
5. St. Louis City 286,578
6. Clay County 257,033
7. Jefferson County 229,336
8. Boone County 187,690
9. Jasper County 124,075
10. Platte County 110,534

11. Cass County 110,394
12. Franklin County 105,879
13. Christian County 93,114
14. Buchanan County 82,911
15. Cape Girardeau County 82,899
16. Cole County 76,969
17. St. Francois County 66,969
18. Lincoln County 63,155
19. Newton County 60,011
20. Taney County 56,821

In the early 20th century, Missouri experienced steady population growth. The 1920 census reported a population of around 3.4 million. By 1950, this had increased to approximately 3.9 million. During the latter half of the 20th century, Missouri’s population continued to grow, albeit at a slower pace compared to some other states. By the 2000 census, the population had reached about 5.6 million.