Illinois District 12
Congressional District in IL • 5 Counties
Illinois's 12th congressional district is represented by Mike Bost, a Republican U.S. representative. Bost won the 2024 general election with 74.2% of the vote. The district has 746,831 residents, a median household income of $68,540 and a median age of 41.6, according to the Census Bureau's 2024 American Community Survey 5-year estimates.
2026 election
FEC filings for the 2026 election. Filing is not ballot access — certified ballots are set by each state.
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District Boundaries
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Demographics
Total Population
Median Household Income
Median Age
College Educated
Poverty Rate
Racial & Ethnic Composition
Racial & Ethnic Composition
2024 Election Results
Mike Bost won by 48.4%
367,629 total votes cast
Federal Spending
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Relevant Legislation
Quick Facts
Representative
Mike BostMajor Counties
Major Cities
Neighboring Districts
Sources and method
· congress-legislators, Census ACS, MEDSL, TIGERweb, Gazetteer, FEC, and 6 more · ACS 2020–2024 5-year estimates
- congress-legislators@unitedstates projectCurrent representative
- American Community SurveyU.S. Census BureauPopulation, income, age and other demographicsACS 2020–2024 5-year estimates · Loaded Oct 29, 2026, 3:12 PM ET
- MEDSL U.S. House 1976–2024MIT Election Data and Science LabLast House election result2024 general election
- TIGERweb district boundariesU.S. Census BureauDistrict map119th Congress boundaries
- Census GazetteerU.S. Census BureauLand area and neighboring districts2024 Gazetteer, 119th Congress districts
- FEC filingsFederal Election Commission2026 candidates and campaign finance
- FREDFederal Reserve Bank of St. Louis (BLS and BEA series)Statewide economic indicators
- Federal agency datasetsEPA ECHO, CMS Hospital Compare, FEMA, CFPB, EIA, College Scorecard, NIH, FDIC BankFindCommunity profile section
- HUD Fair Market Rents and Income LimitsU.S. Department of Housing and Urban DevelopmentHousing affordability section
- Schools, local finance and health dataNCES Common Core of Data, Census ASFIN, CDC PLACESServices and health section
- USAspending.govU.S. Department of the TreasuryFederal spending and relevant bills
- Congress.govLibrary of CongressBills relevant to this district
congress-legislators, MEDSL: CC0 1.0 (public domain dedication) · All other sources: Public domain (17 U.S.C. § 105) · Method: Data sources → · Campaign finance →
The spending narrative is written by AI from USAspending.gov data and is labeled where it appears. It is not a source itself. How we analyze data →
Dates shown where the source reports one. “Loaded” is when CIV.IQ last fetched the record.
Frequently Asked Questions
- Who represents Illinois District 12?
- Mike Bost (Republican) currently represents Illinois District 12 in the U.S. House of Representatives.
- What counties are in Illinois District 12?
- Illinois District 12 includes 5 counties: Madison, St. Clair, Jackson, Williamson, Jefferson.
- What are the major cities in Illinois District 12?
- The major cities in this district include Belleville, Carbondale, East St. Louis, Granite City.
- What is the population of Illinois District 12?
- Illinois District 12 has a population of approximately 746,831 residents.