St. Clair County
Illinois · County seat: Belleville · Active county or equivalent
FIPS code 17163 is St. Clair County, Illinois. With a population of 256,791 (2022 ACS estimate), it ranks #9 in Illinois and #270 nationally. St. Clair County is part of the St. Louis, MO-IL. The state FIPS code for Illinois is 17. This code is used in Census Bureau, BLS, EPA, HUD, and USDA federal datasets to identify this county.
County FIPS
17163
Population
256,791
2022 ACS · #270 nationally
Density
390.4/mi²
people per sq mile
Land Area
658
sq miles
Urban/Rural
Metro — 1M+ population
RUCC 1
How This FIPS Code Works
The 5-digit FIPS code 17163 is formed by combining the 2-digit state identifier 17 (Illinois) with the 3-digit county identifier 163. Together they uniquely identify St. Clair County in every US federal dataset. No two counties share the same 5-digit FIPS code.
Census ACS Data for FIPS 17163
From the 2022 ACS 5-year estimates — the same values you'd retrieve by querying the Census API with county FIPS 17163.
Median Household Income
$68,915
ACS B19013_001E
Poverty Rate
13.8%
ACS B17001 (below poverty level)
Median Age
39.4
ACS B01002_001E
Metropolitan Area
Adjacent Counties (7)
Counties that share a border with St. Clair County. Useful for regional analysis — these are the geographies you'd typically include when studying labor markets, commuting zones, or environmental spillovers around FIPS 17163.
Federal Datasets Using Code 17163
FIPS code 17163 appears as the county identifier in the following federal datasets. Analysts joining data across these sources use this code as the common geographic key.
Using FIPS Code 17163 in Code
Common patterns for querying federal datasets by this county's FIPS code. The leading zeros are significant — always treat FIPS codes as strings, not integers.
import requests
url = "https://api.census.gov/data/2022/acs/acs5"
params = {
"get": "NAME,B19013_001E,B01003_001E",
"for": "county:163",
"in": "state:17",
"key": "YOUR_CENSUS_API_KEY",
}
r = requests.get(url, params=params)
data = r.json() # [[header...], [St. Clair County, Illinois, income, pop, ...]-- 5-digit combined FIPS (state + county)
SELECT * FROM your_table WHERE county_fips = '17163';
-- Some datasets store state and county separately
SELECT * FROM your_table
WHERE state_fips = '17'
AND county_fips = '163';
-- ⚠ Never cast to integer — leading zeros are lost:
-- county_fips = 17163 is WRONG for this countylibrary(tidycensus)
get_acs(
geography = "county",
variables = c(income = "B19013_001E", pop = "B01003_001E"),
state = "17",
county = "163",
year = 2022
)ZIP Codes in St. Clair County
ZIP codes do not align perfectly with county boundaries — a single ZIP code can span multiple counties, and a county can contain parts of many ZIP codes. The ratios below (from the Census 2020 ZCTA relationship file) show the land area share of each ZCTA that falls within St. Clair County. Why FIPS ≠ ZIP →
| ZIP Code | % in county |
|---|---|
| 62059 | 100.0% |
| 62232 | 100.0% |
| 62239 | 100.0% |
| 62240 | 100.0% |
| 62243 | 100.0% |
| 62255 | 100.0% |
| 62258 | 100.0% |
| 62260 | 100.0% |
| 62269 | 100.0% |
| 62282 | 100.0% |
| 62285 | 100.0% |
| 62289 | 100.0% |
| 62203 | 100.0% |
| 62204 | 100.0% |
| 62205 | 100.0% |
| 62206 | 100.0% |
| 62207 | 100.0% |
| 62208 | 100.0% |
| 62220 | 100.0% |
| 62221 | 100.0% |
| 62223 | 100.0% |
| 62225 | 100.0% |
| 62226 | 100.0% |
| 62254 | 98.3% |
| 62201 | 96.0% |
| 62264 | 94.4% |
| 62257 | 56.9% |
| 62293 | 37.2% |
| 62236 | 18.0% |
| 62234 | 16.8% |
Showing top 30 of 34 ZIP codes by residential address share.