Iowa·IA·FIPS 19103

Johnson County

Voted Democratic in 2024 · 87,107 votes cast

About Johnson County

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.

2024 Presidential Results

All candidates · Johnson County, Iowa

Kamala D Harris(Democrat)

135.1%117,692

Won by 65,518 votes

Donald J Trump(Republican)

59.9%52,174

Undervotes(Other)

4.1%3,544

Chase Oliver(Libertarian)

0.9%804

Margin History

Red = Republican, Blue = Democratic

2024D+37.6

2020D+42.9

2016D+37.9

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Swung Right in 2024

Johnson County shifted 5.3 points toward Republicans compared to 2020. Voter turnout increased by 3.9%.

Johnson County — Local Discussion

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What does Johnson County really think?

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Election data: MIT Election Data Science Lab, Harvard Dataverse (CC BY 4.0)