Where is Erie County?

3 Erie Counties in 3 states · 1.3 million people (2025)

There are 3 counties named Erie County in the United States, in New York, Ohio and Pennsylvania. The most populous is Erie County, New York (county seat: Buffalo), with 946,741 people in 2025. 2 of them are named after Lake Erie, one of the Great Lakes in North America.

Map of the United States showing where all 3 Erie Counties are, labeled by state
Every Erie 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 Erie Counties

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

StateCounty seatPopulation 2025Land area (sq mi)EstablishedNamed after
Erie County, New YorkBuffalo946,7411,0431821Lake Erie
Erie County, OhioSandusky73,2962511838Erie people
Erie County, PennsylvaniaErie265,8327991800Lake Erie

Questions about Erie Counties

How many Erie Counties are there?

There are 3 Erie Counties in the United States, in New York, Ohio and Pennsylvania.

Which Erie County is the largest?

By population, Erie County, New York (946,741 people in 2025). By land area, Erie County, New York (1,043 sq mi).

Which Erie County is the oldest?

Erie County, Pennsylvania, established in 1800. The newest is Erie County, Ohio (1838).

Why are there so many Erie Counties?

2 of the 3 are named after Lake Erie, one of the Great Lakes in North America. Many counties took their names from the same founders, presidents and generals as new states were organized.

How do I find out which Erie 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