Jo Daviess County, Illinois
A county in Illinois, ranked 53 of 102 by population.
CountyFIPS 17085
- Population
- 21,594
- -496 (-2.2%) since 2020
- Land area
- 600.9
- square miles. A further 2.9% of the total area is water
- Population density
- 35.9
- people per square mile, computed rather than published
- County seat
- Galena
- Seat of county government.
- Established
- 1827
- 198 years ago
- Largest city
- Galena city
- Population 3,210.
Sources: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026; US Census Bureau, Gazetteer Files, 2025 Gazetteer Files, released 10 September 2025; Wikidata (CC0), Wikidata. Retrieved 30 August 2026.
Satellite view
Aerial imagery of Jo Daviess County with its boundary drawn on top. A map shows you the shape; this shows you what is inside it, and which side of the line a place falls on.
Where Jo Daviess County ranks
Position among the 102 counties of Illinois, and among all 3,144 US counties and county-equivalents. Computed from the figures on this page.
| Measure | Value | In Illinois | Nationally |
|---|---|---|---|
| Population | 21,594 | 53rd of 102 | 1,744th of 3,144 |
| Land area | 600.9 sq mi | 35th of 102 | 1,620th of 3,144 |
| Population density | 35.9 per sq mi | 66th of 102 | 1,773rd of 3,144 |
| Median household income | $73,993 | 28th of 102 | 916th of 3,143 |
Full data for Jo Daviess County
| Measure | Value | Source and vintage |
|---|---|---|
| Population | 21,594 | Vintage 2025 Population Estimates |
| Population in 2020 | 22,090 | Vintage 2025 Population Estimates |
| 2020 estimates base? | 22,075 | Vintage 2025 Population Estimates |
| Land area | 600.9 sq mi | 2025 Gazetteer Files |
| Water area | 17.7 sq mi | 2025 Gazetteer Files |
| Total area | 618.6 sq mi | 2025 Gazetteer Files |
| Population density? | 35.9 per sq mi | Computed: Vintage 2025 estimates divided by 2025 Gazetteer land area |
| Median household income | $73,993 | American Community Survey 2020-2024 5-Year Estimates |
| Median home value | $209,900 | American Community Survey 2020-2024 5-Year Estimates |
| Median age | 51.5 | American Community Survey 2020-2024 5-Year Estimates |
| Households | 10,391 | American Community Survey 2020-2024 5-Year Estimates |
| Housing units | 13,440 | American Community Survey 2020-2024 5-Year Estimates |
Sources: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026; US Census Bureau, Gazetteer Files, 2025 Gazetteer Files, released 10 September 2025; US Census Bureau, American Community Survey, American Community Survey 2020-2024 5-Year Estimates, released 29 January 2026. Population density is computed here, not published: it divides the Vintage 2025 population estimate by the 2025 Gazetteer land area, which are two different Census products. Retrieved 30 August 2026.
How the population changed
The Census Bureau publishes the components behind an estimate, not just the total. For the year to July 2025:
- Births minus deaths
- -82
- 193 births, 275 deaths
- Net migration
- +20
- More people moved in than moved out.
Source: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026. Retrieved 30 August 2026.
The 6 areas bordering Jo Daviess County
Ordered by the length of the border actually shared, which the Census Bureau publishes in its county adjacency file and which no other county reference presents.
| Bordering area | State | Shared border | Population |
|---|---|---|---|
| Lafayette County | Wisconsin | 26 mi | 17,478 |
| Stephenson County | Illinois | 21 mi | 43,220 |
| Carroll County | Illinois | 20 mi | 15,419 |
| Jackson County | Iowa | 17 mi | 19,288 |
| Dubuque County | Iowa | 14 mi | 99,381 |
| Grant County | Wisconsin | 11 mi | 52,446 |
Source: US Census Bureau, County Adjacency File, 2025 County Adjacency File, released 15 September 2025. Retrieved 30 August 2026.
All 102 counties of Illinois
Open the interactive Illinois county map, or jump straight to any of them.
- Adams County
- Alexander County
- Bond County
- Boone County
- Brown County
- Bureau County
- Calhoun County
- Carroll County
- Cass County
- Champaign County
- Christian County
- Clark County
- Clay County
- Clinton County
- Coles County
- Cook County
- Crawford County
- Cumberland County
- De Witt County
- DeKalb County
- Douglas County
- DuPage County
- Edgar County
- Edwards County
- Effingham County
- Fayette County
- Ford County
- Franklin County
- Fulton County
- Gallatin County
- Greene County
- Grundy County
- Hamilton County
- Hancock County
- Hardin County
- Henderson County
- Henry County
- Iroquois County
- Jackson County
- Jasper County
- Jefferson County
- Jersey County
- Jo Daviess County
- Johnson County
- Kane County
- Kankakee County
- Kendall County
- Knox County
- Lake County
- LaSalle County
- Lawrence County
- Lee County
- Livingston County
- Logan County
- Macon County
- Macoupin County
- Madison County
- Marion County
- Marshall County
- Mason County
- Massac County
- McDonough County
- McHenry County
- McLean County
- Menard County
- Mercer County
- Monroe County
- Montgomery County
- Morgan County
- Moultrie County
- Ogle County
- Peoria County
- Perry County
- Piatt County
- Pike County
- Pope County
- Pulaski County
- Putnam County
- Randolph County
- Richland County
- Rock Island County
- Saline County
- Sangamon County
- Schuyler County
- Scott County
- Shelby County
- St. Clair County
- Stark County
- Stephenson County
- Tazewell County
- Union County
- Vermilion County
- Wabash County
- Warren County
- Washington County
- Wayne County
- White County
- Whiteside County
- Will County
- Williamson County
- Winnebago County
- Woodford County
Data on this page last rebuilt 30 August 2026. How these figures are produced.