Ada County, Idaho
Ada County: County in Idaho, United States
About
Ada County is a county located in the U.S. state of Idaho. As of the 2010 census, the population was 392,365 and a population density of 143 people per km². After 9 years in 2019 county had an estimated population of 481,587 inhabitants. Its county seat is Boise. The county was created 160 years ago in 1864.
Quick Facts about Ada County
| Population : | 481,587 (2019) |
| Country : | United States of America |
| State : | Idaho (United States) |
| Area : | 2746 km2 |
| Water as percent of area : | 0.7% |
| Land as percent of area : | 99.3% |
| Named for : | Ada Riggs |
| Altitude : | 3,179 feet / 969 meters |
| Capital : | Boise |
| Establishment : | December 12, 1864 |
| Time Zone : | America/Boise |
| Local time : | 08:20:10 (5th December 2025) |
| Density : | 175 Pop. per km² as of 2019 |
| Population growth : | 18.53% (2010-2019) |
Geography
Ada County is located at 43°27'4"N 116°14'28"W (43.4511200, -116.2410900). It has 5 neighbors: Elmore County, Boise County, Canyon County, Gem County and Owyhee County.
Ada County map
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The largest city of Ada County is Boise with a population of 228,959. Other cities include, Meridian population 114,161, Eagle population 29,796, Kuna population 22,257 and Garden City population 11,969. See all Ada County cities & populated places.
Ada County Populated Places
Cities, towns, neighborhoods & other populated places in Ada County.
| City Name | Population | Title |
|---|---|---|
| Boise | 228,959 | The capital of Idaho. |
| Meridian | 114,161 | The most populous city in Ada County, Idaho. |
| Eagle | 29,796 | City in Ada County, Idaho, United States |
| Kuna | 22,257 | City in Ada County, Idaho, United States |
| Garden City | 11,969 | City in Ada County, Idaho, United States |
| Star | 10,532 | City in Ada County, Idaho, United States |
- Official Website
Official website of Ada County
Ada County has 5 neighbours.
- Elmore County county in Idaho, United States
- Boise County county in Idaho, United States
- Canyon County county in Idaho, United States
- Gem County county in Idaho, United States
- Owyhee County county in Idaho, United States
- Boise
Demographics
The population of Ada County increased by 18.53% in 9 years.
| Year | Population | % Change | Method |
| 2010 | 392,365 | - | census |
| 2011 | 401,262 | 2.22% | estimation process |
| 2012 | 408,862 | 1.86% | estimation process |
| 2013 | 415,951 | 1.7% | estimation process |
| 2014 | 425,471 | 2.24% | estimation process |
| 2015 | 432,862 | 1.71% | estimation process |
| 2016 | 444,486 | 2.62% | estimation process |
| 2017 | 456,548 | 2.64% | estimation process |
| 2018 | 468,764 | 2.61% | estimation process |
| 2019 | 481,587 | 2.66% | estimation process |
Idaho Other Counties (more counties)
| County Name | Population | Title |
|---|---|---|
| Canyon County | 229,849 | County in Idaho, United States |
| Boise | 228,959 | The capital of Idaho. |
| Kootenai County | 165,697 | County in Idaho, United States |
| Bonneville County | 119,062 | County in Idaho, United States |
| Meridian | 114,161 | The most populous city in Ada County, Idaho. |
| Nampa | 99,277 | The most populous city in Canyon County, Idaho. |
| Bannock County | 87,808 | County in Idaho, United States |
| Twin Falls County | 86,878 | County in Idaho, United States |
| Idaho Falls | 62,888 | The most populous city in Bonneville County, Idaho. |
| Caldwell | 58,481 | The most populous city in Canyon County, Idaho. |
| Pocatello | 56,637 | The most populous city in Bannock County, Idaho. |
| Coeur d'Alene | 52,414 | A city in Kootenai County, Idaho. |
| Twin Falls | 50,197 | The most populous city in Twin Falls County, Idaho. |
| Bingham County | 46,811 | County in Idaho, United States |
| Bonner County | 45,739 | County in Idaho, United States |
| Nez Perce County | 40,408 | County in Idaho, United States |
