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Johnson County

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Also known as Johnson County, Iowa, Johnson County, IA

county in Iowa, United States

Key facts

Country
United States
State
Iowa
Founded
December 21, 1837 (created), July 4, 1838 (organized)
Named after
Richard Mentor Johnson (1837–2020), Lulu Johnson (since 2020)
Seat
Iowa City
Largest city
Iowa City
Total
623.063 sq mi (1,613.73 km )
Land
612.997 sq mi (1,587.65 km )
Water
10.066 sq mi (26.07 km ) 1.62%
Estimate 2025
160,044
Density
249.355/sq mi (96.2766/km )
Time zone
UTC−6 ( Central )
Summer dst
UTC−5 ( CDT )
Congressional district
1st
Website
johnsoncountyiowa.gov

via Wikipedia infobox

Wikidata facts

Located in
Iowa
Contains
Iowa City
Capital
Iowa City
Population
152854
Area
1614
Shares border with
Benton County
Official website
www.johnson-county.com
Image
Johnson county courhouse iowa.jpg
Households
60430
Show 9 more facts
Commons category
Johnson County, Iowa
topic's main category
Category:Johnson County, Iowa
inception
1837-12-21
category for people born here
Category:Births in Johnson County, Iowa
category of associated people
Category:People from Johnson County, Iowa
water as percent of area
1.5
native label
Johnson County
per capita income
35875
Sources (9)

via Wikidata · CC0

~12 min read

Encyclopedic overview

Johnson County is located in the U.S. state of Iowa. As of the 2020 census, the population was 152,854, and was estimated to be 160,044 in 2025, making it the fourth-most populous county in Iowa. The county seat and the largest city is Iowa City, home of the University of Iowa. Johnson County is included in the Iowa City metropolitan area, which is also included in the Cedar Rapids-Iowa City Corridor Combined Statistical Area.

History

Excerpted from Wikipedia’s “Johnson County” article, available under the CC BY-SA 4.0 licence.

On the map