St. Clair County, IL Demographics & ZIP Codes
St. Clair County, Illinois demographics and median household income by ZIP code — 27 ZIP codes — population 248,247 — avg. income $68,258 — avg. home value $139,542. Compare income, housing, and ZIP-level data on US5.
St. Clair County demographics
St. Clair County, Illinois covers 27 ZIP codes, with a combined ZIP-area population of about 248,247.
Median household income in St. Clair County
The average median household income across ZIP codes in St. Clair County, Illinois is about $68,258 — about 13% below the IL ZIP average ($78,143), and about 9% below the U.S. median ($75,149).
Among ZIPs with income data, 62285 (Smithton) is near the top at about $118,413, while 62201 (Fairmont City) is near the bottom at about $21,658.
Housing in St. Clair County
For housing in St. Clair County, Illinois, the average median home value is about $139,542 and the average median rent is about $725.
The most populous ZIP is 62269 (O'Fallon) with about 35,536 residents. Use the table below to compare ZIP codes across the county.
ZIP codes in St. Clair County
Sort by population, income, or home value. Click a column header to toggle ascending / descending.
| ZIP | City | County | State | Population ↓ | Income | Home value |
|---|---|---|---|---|---|---|
| 62269 | O'Fallon | St. Clair County | IL | 35,536 | $100,167 | $274,200 |
| 62221 | Shiloh | St. Clair County | IL | 29,281 | $78,619 | $207,200 |
| 62226 | Swansea | St. Clair County | IL | 28,543 | $66,018 | $162,500 |
| 62220 | Belleville | St. Clair County | IL | 19,391 | $65,261 | $141,300 |
| 62208 | Fairview Heights | St. Clair County | IL | 16,653 | $78,423 | $167,900 |
| 62223 | Belleville | St. Clair County | IL | 16,269 | $69,620 | $149,600 |
| 62206 | Cahokia | St. Clair County | IL | 13,155 | $39,520 | $57,700 |
| 62258 | Mascoutah | St. Clair County | IL | 10,292 | $90,417 | $229,500 |
| 62232 | Caseyville | St. Clair County | IL | 7,480 | $64,268 | $114,800 |
| 62207 | Centreville | St. Clair County | IL | 6,801 | $29,184 | $54,400 |
| 62243 | Freeburg | St. Clair County | IL | 6,522 | $93,328 | $268,200 |
| 62260 | Millstadt | St. Clair County | IL | 6,518 | $93,929 | $229,600 |
| 62254 | Lebanon | St. Clair County | IL | 6,339 | $89,500 | $196,600 |
| 62205 | East St. Louis | St. Clair County | IL | 5,760 | $41,059 | $46,200 |
| 62225 | Scott AFB | St. Clair County | IL | 5,606 | $91,988 | — |
| 62203 | East St. Louis | St. Clair County | IL | 5,539 | $41,134 | $72,700 |
| 62201 | Fairmont City | St. Clair County | IL | 5,017 | $21,658 | $56,100 |
| 62204 | Washington Park | St. Clair County | IL | 4,824 | $36,789 | $48,200 |
| 62239 | Dupo | St. Clair County | IL | 4,381 | $57,793 | $111,700 |
| 62285 | Smithton | St. Clair County | IL | 4,187 | $118,413 | $265,300 |
| 62264 | New Athens | St. Clair County | IL | 3,152 | $61,174 | $137,100 |
| 62240 | Dupo | St. Clair County | IL | 1,994 | $70,298 | $84,800 |
| 62257 | Marissa | St. Clair County | IL | 1,960 | $66,848 | $119,200 |
| 62255 | Lenzburg | St. Clair County | IL | 1,231 | $78,250 | $153,400 |
| 62059 | Brooklyn | St. Clair County | IL | 811 | $37,656 | $37,200 |
| 62282 | St. Libory | St. Clair County | IL | 620 | $113,167 | $168,800 |
| 62289 | Summerfield | St. Clair County | IL | 385 | $48,472 | $73,900 |
Frequently asked questions
What are the demographics of St. Clair County?
St. Clair County, Illinois has a combined ZIP-area population of about 248,247 across 27 ZIP codes. Browse the ZIP table for population, income, and housing by code.
What is the median household income in St. Clair County?
The average median household income across ZIP codes in St. Clair County, Illinois is about $68,258, about 13% below the state ZIP average ($78,143), and about 9% below the U.S. median ($75,149). Average median home value is about $139,542. Among ZIPs with data, 62285 (Smithton) is near the top ($118,413) and 62201 (Fairmont City) is near the bottom ($21,658).
How many ZIP codes are in St. Clair County?
St. Clair County, Illinois includes 27 ZIP codes on US5. Each row links to demographics, median income, and housing for that code.
Where can I find ZIP code demographics for St. Clair County?
This page lists ZIP codes in St. Clair County, Illinois with population, median household income, and home value. Select a ZIP for a full demographics profile.