Monroe County, Illinois

Monroe County profile, demographic data, and geographic information.

Local Government & Public Administration

Authoritative general-purpose local government units serving this area U.S. Census Bureau GUS (2026) / GMAF

Government Unit	Unit Type	Jurisdiction Role	Contact / Address
COUNTY OF MONROE GUS Population: 34,969 (2024) ID: 102552	County	Official County Government	Contact: TREASURER 100 S MAIN ST, WATERLOO IL 62298
CITY OF WATERLOO GUS Population: 11,165 (2024) ID: 162543	Municipal	Municipal Government Within County	Contact: COLLECTOR-BUDGET OFFICER 100 W 4TH ST, WATERLOO IL 62298-1333
CITY OF COLUMBIA GUS Population: 10,919 (2024) ID: 162540	Municipal	Municipal Government Within County	Contact: ACCOUNTING MANAGER 208 S RAPP AVE, COLUMBIA IL 62236-2329
VILLAGE OF VALMEYER GUS Population: 1,214 (2024) ID: 162542	Municipal	Municipal Government Within County	Contact: TREASURER 626 S MEYER AVE, VALMEYER IL 62295-3117
VILLAGE OF HECKER GUS Population: 421 (2024) ID: 125021	Municipal	Municipal Government Within County	Contact: PRESIDENT PO BOX 176, HECKER IL 62248-0176
VILLAGE OF MAEYSTOWN GUS Population: 149 (2024) ID: 162541	Municipal	Municipal Government Within County	Contact: TREASURER PO BOX 54, MAEYSTOWN IL 62256-0054
VILLAGE OF FULTS GUS Population: 26 (2024) ID: 102791	Municipal	Municipal Government Within County	Contact: TREASURER PO BOX 3, FULTS IL 62244