Where is Summit County?

3 Summit Counties in 3 states · 613,034 people (2025)

There are 3 counties named Summit County in the United States, in Colorado, Ohio and Utah. The most populous is Summit County, Ohio (county seat: Akron), with 538,376 people in 2025.

Map of the United States showing where all 3 Summit Counties are, labeled by state
Every Summit County in the United States (red), labeled with its state. Boundaries: U.S. Census Bureau, 2025. Free to use with attribution (CC BY 4.0).

All 3 Summit Counties

Sorted by state. Each link opens the county's map.

StateCounty seatPopulation 2025Land area (sq mi)EstablishedNamed after
Summit County, ColoradoBreckenridge31,5176081861Continental Divide of the Americas
Summit County, OhioAkron538,3764131840–
Summit County, UtahCoalville43,1411,8711854–

Questions about Summit Counties

How many Summit Counties are there?

There are 3 Summit Counties in the United States, in Colorado, Ohio and Utah.

Which Summit County is the largest?

By population, Summit County, Ohio (538,376 people in 2025). By land area, Summit County, Utah (1,871 sq mi).

Which Summit County is the oldest?

Summit County, Ohio, established in 1840. The newest is Summit County, Colorado (1861).

How do I find out which Summit County an address is in?

Open the county map of the state: it has a search box for cities, towns and ZIP codes. On a phone, the "what county am I in" tool on our sister site uses your location.

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Other common county names