County data desk
Which Missouri counties have the youngest populations? Pulaski County, where 10.1 percent of residents are aged 65 and over.
The other end of the share column. Twenty counties sit furthest below the statewide figure of 18.7 percent, and between them they hold half of Missouri's people and 45.6 percent of its older adults.
| # | County | Share 65 and over | Aged 65 and over | Total population | Aged 85 and over |
|---|---|---|---|---|---|
| 1 | Pulaski County | 10.1% | 5,466 | 53,964 | 489 |
| 2 | Johnson County | 13.9% | 7,767 | 55,880 | 750 |
| 3 | Boone County | 14.5% | 27,911 | 192,154 | 2,936 |
| 4 | Lincoln County | 15.5% | 10,226 | 65,888 | 888 |
| 5 | Webster County | 15.9% | 6,678 | 42,041 | 580 |
| 6 | Adair County | 15.9% | 4,086 | 25,660 | 495 |
| 7 | Clay County | 16.1% | 42,284 | 263,370 | 4,149 |
| 8 | Jackson County | 16.6% | 120,879 | 727,362 | 12,647 |
| 9 | Jasper County | 16.7% | 21,154 | 126,479 | 2,222 |
| 10 | St. Louis city | 16.8% | 46,992 | 279,695 | 4,630 |
| 11 | Platte County | 16.9% | 19,125 | 113,207 | 1,880 |
| 12 | McDonald County | 17.0% | 4,088 | 24,054 | 298 |
| 13 | Moniteau County | 17.2% | 2,623 | 15,294 | 309 |
| 14 | Christian County | 17.5% | 16,797 | 96,045 | 1,669 |
| 15 | Randolph County | 17.8% | 4,275 | 24,077 | 499 |
| 16 | Greene County | 17.8% | 54,779 | 307,942 | 6,293 |
| 17 | Jefferson County | 17.9% | 41,443 | 231,888 | 3,040 |
| 18 | St. Francois County | 17.9% | 12,100 | 67,503 | 1,226 |
| 19 | Phelps County | 18.1% | 8,253 | 45,672 | 976 |
| 20 | St. Charles County | 18.1% | 76,887 | 423,726 | 8,071 |
Statewide, 18.7 percent of Missouri residents are aged 65 and over. Twenty five counties sit below that line; the 21st lowest, Lawrence County, reports 18.2 percent. Ties in the displayed one decimal share are ordered on the unrounded ratio, which is why Webster precedes Adair and Phelps precedes St. Charles.
Methodology
- Metric
- Residents aged 65 and over as a share of total county population, sorted ascending, lowest share first. Where two counties display the same share to one decimal, the order follows the unrounded division of the two published columns. This is the same column the statewide oldest counties page sorts descending, read from the opposite end.
- Source
- U.S. Census Bureau, Population Estimates Program, Vintage 2024 county characteristics file cc-est2024-agesex-29.csv, columns AGE65PLUS_TOT, AGE85PLUS_TOT and POPESTIMATE, rows coded YEAR 6.
- Reference date
- July 1, 2024.
- Item set
- All 115 Missouri county equivalents. The 20 lowest shares are published here. Measured against the top 20 by share, the two item sets have no county in common.
- Pulled
- September 10, 2026
- Licence
- Public domain, a work of the United States government.
Low share, high count: the youngest counties are the big ones
The twenty counties on this page hold 3,181,901 residents, 50.9 percent of Missouri's 6,245,466, and 533,813 residents aged 65 and over, 45.6 percent of the statewide 1,169,583. The twenty oldest counties by share, the mirror image of this table, hold 244,825 residents and 68,955 older adults, 5.9 percent of the state.
Jackson County, 8th lowest by share at 16.6 percent, holds 120,879 residents aged 65 and over, the second largest count in Missouri. Boone County, 3rd lowest at 14.5 percent, holds 27,911. St. Charles County, 20th lowest at 18.1 percent, holds 76,887. A low share does not mean few older adults; in this state it usually means a large county where the working age population is larger still.
The count ranking that makes this explicit is on the counties by count page. Thirteen of the twenty counties here also appear in that top 25, at entirely different positions.
Four of the seven St. Louis region counties are on this page
Tinted chips mark the three regional counties that fall outside the bottom 20. Rank is the county's position among all 115 rows sorted lowest share first.
Lincoln County, at 15.5 percent, is the 4th lowest share in Missouri. The city of St. Louis is 10th at 16.8 percent, Jefferson County 17th at 17.9 percent and St. Charles County 20th at 18.1 percent. Warren County at 19.5 percent, St. Louis County at 20.1 percent and Franklin County at 20.3 percent sit above the statewide line and outside this table.
None of the seven reaches the statewide top 20 by share either. The region's counties cluster in the middle of the column with a tail into the youngest end, which is consistent with a metropolitan area that is still adding working age residents in its outer counties.
What the file does and does not say about the lowest rows
The three lowest shares, Pulaski County at 10.1 percent, Johnson County at 13.9 percent and Boone County at 14.5 percent, sit well apart from the rest of the table. The Census file records residents by age and offers no explanation for any row. Readers who know the state will recognise those three as counties that host a large Army post and two state universities; that reading is the reader's, not the file's, and this desk records it as context rather than as a finding.
A share moves with both of its parts. It falls when younger residents arrive as well as when older residents leave, and this single reference date cannot separate the two. Nothing here is a forecast, and nothing here describes health, need or the use of caregiver services. Sources, column codes and limits are on the methodology page.
Back to the region at a glance · The oldest counties, the same column descending