Where is Decatur County?

5 Decatur Counties in 5 states · 78,199 people (2025)

There are 5 counties named Decatur County in the United States, in Georgia, Indiana, Iowa, Kansas and Tennessee. The most populous is Decatur County, Georgia (county seat: Bainbridge), with 29,432 people in 2025. 5 of them are named after Stephen Decatur, United States Navy officer.

Map of the United States showing where all 5 Decatur Counties are, labeled by state
Every Decatur 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 5 Decatur Counties

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

StateCounty seatPopulation 2025Land area (sq mi)EstablishedNamed after
Decatur County, GeorgiaBainbridge29,4325971823Stephen Decatur
Decatur County, IndianaGreensburg26,5763731822Stephen Decatur
Decatur County, IowaLeon7,6555321846Stephen Decatur
Decatur County, KansasOberlin2,7168941873Stephen Decatur
Decatur County, TennesseeDecaturville11,8203341845Stephen Decatur

Questions about Decatur Counties

How many Decatur Counties are there?

There are 5 Decatur Counties in the United States, in Georgia, Indiana, Iowa, Kansas and Tennessee.

Which Decatur County is the largest?

By population, Decatur County, Georgia (29,432 people in 2025). By land area, Decatur County, Kansas (894 sq mi).

Which Decatur County is the oldest?

Decatur County, Indiana, established in 1822. The newest is Decatur County, Kansas (1873).

Why are there so many Decatur Counties?

5 of the 5 are named after Stephen Decatur, United States Navy officer. Many counties took their names from the same founders, presidents and generals as new states were organized.

How do I find out which Decatur 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