A metro-east county is among the 10 richest in IL, analysis says. Here’s the full list
Lake County was recently named the wealthiest county in Illinois, according to finance website SmartAsset, and one southwestern Illinois locale cracked the top 10, as well.
Monroe County was named the seventh wealthiest in the state in SmartAsset’s analysis. The county has a median income of $100,685, according to the report. The metro-east county moved up one place from 2023’s ranking, when it was named the eighth wealthiest in the Land of Lincoln.
SmartAsset used sources such as the U.S. Census Bureau, real estate site Zillow and the U.S. Internal Revenue Service to compile the ranking. The three metrics considered included investment income, property value and median income. The most recent ranking reflects data from 2024, according to SmartAsset.
Statewide, Illinois’ median household income is $81,702, according to the Census Bureau, and 11.6% of residents live in poverty.
Monroe County has the eighth highest median home value in Illinois, SmartAsset’s analysis found, at $296,096. The county has a median listing price of $414,200, real estate site Realtor.com reports, a 14.1% increase from January 2024 to January 2025.
St. Clair County came in as the 31st most wealthy in Illinois, with a median income of $68,915.
Here’s how the 10 wealthiest counties in Illinois stacked up, from SmartAsset.
The wealthiest counties in Illinois
1. Lake County
Median income: $104,553
Investment income: $144,643
Median home value: $353,559
2. DuPage County
Median income: $107,035
Investment income: $72,712
Median home value: $401,641
3. Kendall County
Median income: $106,358
Investment income: $26,804
Median home value: $360,529
4. Will County
Median income: $103,678
Investment income: $35,444
Median home value: $339,705
5. McHenry County
Median income: $100,101
Investment income: $61,544
Median home value: $333,572
6. Kane County
Median income: $96,400
Investment income: $49,121
Median home value: $343,964
7. Monroe County
Median income: $100,685
Investment income: $34,250
Median home value: $296,096
8. Cook County
Median income: $78,304
Investment income: $116,986
Median home value: $306,108
9. Grundy County
Median income: $89,993
Investment income: $39,720
Median home value: $290,793
10. Boone County
Median income: $80,502
Investment income: $44,572
Median home value: $250,642
Several counties switched places from 2023’s ranking, which named these the 10 wealthiest Illinois counties: DuPage, Lake, Kendall, Will, Kane, Cook, McHenry, Monroe, Grundy and DeKalb.
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