STATE ยท ID

Counties in Idaho

Idaho has 44 counties and county equivalents. The most populous is Ada County with 524,673 people (Census 2023 estimate).

CountyTypeFIPSPopulation (2023)
Ada Countycounty16001524,673
Adams Countycounty160034,903
Bannock Countycounty1600590,400
Bear Lake Countycounty160076,766
Benewah Countycounty1600910,369
Bingham Countycounty1601150,395
Blaine Countycounty1601325,041
Boise Countycounty160158,517
Bonner Countycounty1601752,547
Bonneville Countycounty16019131,366
Boundary Countycounty1602113,557
Butte Countycounty160232,758
Camas Countycounty160251,232
Canyon Countycounty16027257,674
Caribou Countycounty160297,219
Cassia Countycounty1603125,696
Clark Countycounty16033801
Clearwater Countycounty160359,214
Custer Countycounty160374,523
Elmore Countycounty1603929,724
Franklin Countycounty1604115,494
Fremont Countycounty1604314,196
Gem Countycounty1604521,071
Gooding Countycounty1604716,061
Idaho Countycounty1604917,890
Jefferson Countycounty1605134,198
Jerome Countycounty1605325,479
Kootenai Countycounty16055185,010
Latah Countycounty1605741,301
Lemhi Countycounty160598,441
Lewis Countycounty160613,739
Lincoln Countycounty160635,450
Madison Countycounty1606554,547
Minidoka Countycounty1606722,480
Nez Perce Countycounty1606942,987
Oneida Countycounty160714,953
Owyhee Countycounty1607312,722
Payette Countycounty1607527,279
Power Countycounty160778,253
Shoshone Countycounty1607914,026
Teton Countycounty1608112,549
Twin Falls Countycounty1608395,156
Valley Countycounty1608512,644
Washington Countycounty1608711,425

Sources: U.S. Census Bureau geographic reference files; Census Bureau Population Estimates, Vintage 2023. Last reviewed 2026-10-27. Looking for yours? Find your county.