Where is Allen County?

4 Allen Counties in 4 states · 538,048 people (2025)

There are 4 counties named Allen County in the United States, in Indiana, Kansas, Kentucky and Ohio. The most populous is Allen County, Indiana (county seat: Fort Wayne), with 402,329 people in 2025. 2 of them are named after John Allen, American politician and army officer (1771–1813).

Map of the United States showing where all 4 Allen Counties are, labeled by state
Every Allen 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 4 Allen Counties

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

StateCounty seatPopulation 2025Land area (sq mi)EstablishedNamed after
Allen County, IndianaFort Wayne402,3296571824John Allen
Allen County, KansasIola12,3025001855William Allen
Allen County, KentuckyScottsville22,5363441815John Allen
Allen County, OhioLima100,8814031820Ethan Allen

Questions about Allen Counties

How many Allen Counties are there?

There are 4 Allen Counties in the United States, in Indiana, Kansas, Kentucky and Ohio.

Which Allen County is the largest?

By population, Allen County, Indiana (402,329 people in 2025). By land area, Allen County, Indiana (657 sq mi).

Which Allen County is the oldest?

Allen County, Kentucky, established in 1815. The newest is Allen County, Kansas (1855).

Why are there so many Allen Counties?

2 of the 4 are named after John Allen, American politician and army officer (1771–1813). Many counties took their names from the same founders, presidents and generals as new states were organized.

How do I find out which Allen 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