Hamilton County
Also known as Hamilton County, Indiana, Hamilton County, IN
county in Indiana, United States
Key facts
- Country
- United States
- State
- Indiana
- Named after
- Alexander Hamilton
- Seat
- Noblesville
- Largest city
- Fishers
- Total
- 402.44 sq mi (1,042.3 km )
- Land
- 394.27 sq mi (1,021.2 km )
- Water
- 8.17 sq mi (21.2 km ) 2.03%
- Estimate 2025
- 387,036
- Density
- 940/sq mi (364/km )
- Time zone
- UTC−5 ( Eastern )
- Summer dst
- UTC−4 ( EDT )
- Congressional district
Article
Hamilton County is a county in the U.S. state of Indiana. The 2020 United States census recorded a population of 347,467. The county seat is Noblesville.
Hamilton County is part of the Indianapolis metropolitan area. Since the beginning of the 21st century, Hamilton County has been the second most populous county in Central Indiana. It is the highest-income county in Indiana, and one of the highest-income counties in the United States.