County data desk
Which St. Louis county has the most residents aged 65 and over? St. Louis County, with 199,345.
Fifteen counties, ranked on one column of one public file: residents aged 65 and over, counted as of July 1, 2024. Population, count and share for every county in the region.
Methodology
- Metric
- Residents aged 65 and over, count, sorted descending. No weighting, no scoring, no editorial adjustment.
- Source
- U.S. Census Bureau, Population Estimates Program, Vintage 2024 county characteristics files cc-est2024-agesex-29.csv and cc-est2024-agesex-17.csv, column AGE65PLUS_TOT, rows coded YEAR 6.
- Reference date
- July 1, 2024. YEAR 6 is the sixth reference period in the 2020 to 2024 vintage series.
- Item set
- The 15 counties of the St. Louis MO-IL metropolitan statistical area as delineated by the Office of Management and Budget. The independent city of St. Louis is a county equivalent and is listed as its own row.
- Pulled
- September 10, 2026
- Licence
- Public domain, a work of the United States government.
| # | County | State | Total population | Aged 65 and over | Share |
|---|---|---|---|---|---|
| 1 | St. Louis County | Missouri | 992,929 | 199,345 | 20.1% |
| 2 | St. Charles County | Missouri | 423,726 | 76,887 | 18.1% |
| 3 | Madison County | Illinois | 263,017 | 51,448 | 19.6% |
| 4 | St. Louis city | Missouri | 279,695 | 46,992 | 16.8% |
| 5 | St. Clair County | Illinois | 251,149 | 46,500 | 18.5% |
| 6 | Jefferson County | Missouri | 231,888 | 41,443 | 17.9% |
| 7 | Franklin County | Missouri | 107,256 | 21,777 | 20.3% |
| 8 | Lincoln County | Missouri | 65,888 | 10,226 | 15.5% |
| 9 | Macoupin County | Illinois | 43,895 | 9,911 | 22.6% |
| 10 | Warren County | Missouri | 38,478 | 7,504 | 19.5% |
| 11 | Monroe County | Illinois | 34,969 | 7,471 | 21.4% |
| 12 | Clinton County | Illinois | 37,087 | 7,320 | 19.7% |
| 13 | Jersey County | Illinois | 21,150 | 4,663 | 22.0% |
| 14 | Bond County | Illinois | 16,576 | 3,272 | 19.7% |
| 15 | Calhoun County | Illinois | 4,224 | 1,077 | 25.5% |
Regional total: 535,836 residents aged 65 and over out of 2,811,927, or 19.1 percent.
Reading the ranking
The count ranking is dominated by one jurisdiction. St. Louis County holds 199,345 residents aged 65 and over, which is 37.2 percent of the regional total and more than the next two counties together. St. Charles County, second at 76,887, holds more residents aged 65 and over than the nine smallest counties in the region combined.
Below the top five the drop is steep. Jefferson County reports 41,443 and Franklin County 21,777, and from there the counts fall into four figures. Seven of the fifteen counties hold fewer than 10,000 residents aged 65 and over, and together those seven account for 7.7 percent of the region.
Count and share describe different things, and this page ranks only the first. Calhoun County, Illinois, sits last here with 1,077 residents aged 65 and over, yet it carries the highest share in the region at 25.5 percent of its 4,224 residents. A ranking by share is published separately for all 115 Missouri counties on the oldest counties page.
What this ranking is not
These are population estimates, not service records. The column counts residents by age. It does not identify anyone as needing assistance, and nothing on this page should be read as a statement about health, care needs or clinical status.
The estimates are modelled by the Census Bureau from a 2020 base, updated with administrative records on births, deaths and migration. They carry the uncertainty any estimate carries, and the smallest counties on this list carry proportionally the most. The Bureau documents its methods in the population estimates methodology.
Supply of caregiver services is a separate question with a separate file. It is answered, county by county, on the supply ratio page.
Back to the region at a glance · Sources, vintage and limits