Where Is Delaware County? All 6 Delaware Counties on a Map

Where is Delaware County?

6 Delaware Counties in 6 states · 1 million people (2025)

There are 6 counties named Delaware County in the United States, in Indiana, Iowa, New York, Ohio, Oklahoma and Pennsylvania. The most populous is Delaware County, Pennsylvania (county seat: Media), with 580,937 people in 2025. 3 of them are named after Lenape, indigenous people of North America.

All 6 Delaware Counties

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

State	County seat	Population 2025	Land area (sq mi)	Established	Named after
Delaware County, Indiana	Muncie	113,106	392	1827	Lenape
Delaware County, Iowa	Manchester	17,674	578	1837	Delaware
Delaware County, New York	Delhi	44,305	1,443	1797	Delaware River
Delaware County, Ohio	Delaware	242,032	443	1808	Lenape
Delaware County, Oklahoma	Jay	41,910	738	1907	Lenape
Delaware County, Pennsylvania	Media	580,937	184	1789	Delaware River

Questions about Delaware Counties

How many Delaware Counties are there?

There are 6 Delaware Counties in the United States, in Indiana, Iowa, New York, Ohio, Oklahoma and Pennsylvania.

Which Delaware County is the largest?

By population, Delaware County, Pennsylvania (580,937 people in 2025). By land area, Delaware County, New York (1,443 sq mi).

Which Delaware County is the oldest?

Delaware County, Pennsylvania, established in 1789. The newest is Delaware County, Oklahoma (1907).

Why are there so many Delaware Counties?

3 of the 6 are named after Lenape, indigenous people of 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 Delaware 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.

What county am I in? →