Pennsylvania·PA·FIPS 42003

Allegheny County

Voted Democratic in 2024 · 720,504 votes cast

About Allegheny County

Allegheny County is a large urban county in Pennsylvania, United States. As of the 2025 census estimate, the population was 1,225,035, a 2% decrease of 25,543 residents since 2020, making it the state's second-most populous county, after Philadelphia County. Its county seat and most populous city is Pittsburgh, Pennsylvania's second most populous city. The county is part of the Greater Pittsburgh region of the commonwealth, and is the center of the Pittsburgh media market.

2024 Presidential Results

All candidates · Allegheny County, Pennsylvania

Kamala D Harris(Democrat)

119.3%859,832

Won by 292,642 votes

Donald J Trump(Republican)

78.7%567,190

Other(Other)

1.0%7,382

Chase Oliver(Libertarian)

0.9%6,604

Margin History

Red = Republican, Blue = Democratic

2024D+20.3

2020D+20.4

2016D+16.6

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Swung Right in 2024

Allegheny County shifted 0.1 points toward Republicans compared to 2020. Voter turnout increased by 0.1%.

Allegheny County — Local Discussion

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What does Allegheny County really think?

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