Data / Rankings / Population / Counties in Idaho

Counties in Idaho by population, 2025

Ada County had the highest population of 44 counties in 2025, at 546,141. Clark County had the lowest, at 783. The median was 15,049 and the figure for Idaho was 2.03 million. Source: the U.S. Census Bureau.

Highest546,141Ada County
Lowest783Clark County
Median15,04944 counties
Idaho2,029,733History

All counties, 2025

CSVChart (SVG)

Ada CountyAda County: 546,141 persons546,141Canyon CountyCanyon County: 275,123 persons275,123Kootenai CountyKootenai County: 191,864 persons191,864Bonneville CountyBonneville County: 135,771 persons135,771Twin Falls CountyTwin Falls County: 97,539 persons97,539Bannock CountyBannock County: 91,591 persons91,591Madison CountyMadison County: 55,172 persons55,172Bonner CountyBonner County: 54,420 persons54,420Bingham CountyBingham County: 51,153 persons51,153Nez Perce CountyNez Perce County: 42,905 persons42,905Latah CountyLatah County: 41,842 persons41,842Jefferson CountyJefferson County: 35,297 persons35,297Elmore CountyElmore County: 29,465 persons29,465Payette CountyPayette County: 27,824 persons27,824Cassia CountyCassia County: 26,397 persons26,397Jerome CountyJerome County: 26,362 persons26,362Blaine CountyBlaine County: 25,517 persons25,517Minidoka CountyMinidoka County: 22,911 persons22,911Gem CountyGem County: 21,773 persons21,773Idaho CountyIdaho County: 17,874 persons17,874Gooding CountyGooding County: 16,446 persons16,446Franklin CountyFranklin County: 15,889 persons15,889Fremont CountyFremont County: 14,208 persons14,208Shoshone CountyShoshone County: 14,130 persons14,130Boundary CountyBoundary County: 13,997 persons13,997Teton CountyTeton County: 13,254 persons13,254Valley CountyValley County: 12,831 persons12,831Owyhee CountyOwyhee County: 12,661 persons12,661Washington CountyWashington County: 11,583 persons11,583Benewah CountyBenewah County: 10,508 persons10,508Clearwater CountyClearwater County: 9,118 persons9,118Boise CountyBoise County: 8,545 persons8,545Lemhi CountyLemhi County: 8,474 persons8,474Power CountyPower County: 8,246 persons8,246Caribou CountyCaribou County: 7,252 persons7,252Bear Lake CountyBear Lake County: 6,727 persons6,727Lincoln CountyLincoln County: 5,603 persons5,603Oneida CountyOneida County: 5,085 persons5,085Adams CountyAdams County: 5,013 persons5,013Custer CountyCuster County: 4,636 persons4,636Lewis CountyLewis County: 3,704 persons3,704Butte CountyButte County: 2,783 persons2,783Camas CountyCamas County: 1,316 persons1,316Clark CountyClark County: 783 persons783
persons. Source: U.S. Census Bureau. Retrieved 2026-10-08.

Full ranking

RankCounties2025
persons		Change on 2024
1Ada County546,141+2%
2Canyon County275,123+2.9%
3Kootenai County191,864+1.8%
4Bonneville County135,771+1.5%
5Twin Falls County97,539+1.1%
6Bannock County91,591+0.7%
7Madison County55,172+0.4%
8Bonner County54,420+1.4%
9Bingham County51,153+0.4%
10Nez Perce County42,9050%
11Latah County41,842+0.2%
12Jefferson County35,297+1.3%
13Elmore County29,465-0.4%
14Payette County27,824+0.5%
15Cassia County26,397+0.7%
16Jerome County26,362+0.3%
17Blaine County25,517-0.7%
18Minidoka County22,911+0.8%
19Gem County21,773+1.5%
20Idaho County17,8740%
21Gooding County16,446+0.3%
22Franklin County15,889+1.4%
23Fremont County14,208-1%
24Shoshone County14,130+0.7%
25Boundary County13,997+1%
26Teton County13,254+1.1%
27Valley County12,831+0.1%
28Owyhee County12,661-0.8%
29Washington County11,583+0.8%
30Benewah County10,508+0.2%
31Clearwater County9,118-0.3%
32Boise County8,545+0.5%
33Lemhi County8,474+0.8%
34Power County8,246-1%
35Caribou County7,252+0.4%
36Bear Lake County6,727+0.4%
37Lincoln County5,603-0.5%
38Oneida County5,085+1.4%
39Adams County5,013+0.1%
40Custer County4,636+1.2%
41Lewis County3,704-0.2%
42Butte County2,783+2.1%
43Camas County1,316+2.3%
44Clark County783+0.1%

Other periods

About this ranking

Resident population. Spain and the EU: 1 January, with Spanish figures from the official municipal register (Padrón). United States: Census Bureau population estimates for 1 July. Other countries and the World: World Bank mid-year estimates, which count all residents regardless of legal status or citizenship.

For Denmark, Statistics Denmark counts the registered resident population on 1 January. Greenland and the Faroe Islands are excluded. The annual series selects the first-quarter reference date from FOLK1A. The World Bank series exists for every country, so use it (through compare) to rank countries on one basis.

Every value in the ranking comes from the same publisher and the same period, so the counties are compared on one definition. Equal values share a rank.

How to cite

U.S. Census Bureau. Annual estimates of the resident population for the United States, states and counties, 1 July (Population Estimates Program). https://www2.census.gov/programs-surveys/popest/datasets/2020-2025/. Retrieved 2026-10-08.

Use this data in your AI agent

Invokely serves this figure to AI assistants through MCP and to code through a REST API, with the source and citation attached. Ask your assistant:

Rank Counties in Idaho by population using official data, and cite the source.
rank_places {"indicator":"population","level":"province","within":"Idaho","limit":10}
GET https://invokely.ai/api/v1/rank?indicator=population&level=province&within=Idaho&limit=10

Connect Claude, ChatGPT or Cursor in one step. The trial answers 25 calls a day without an account.

Questions

Which county has the highest population?

Ada County, with 546,141 in 2025, according to the U.S. Census Bureau.

Which county has the lowest population?

Clark County, with 783 in 2025.

Where does this ranking come from?

Every value comes from one source and one period, so the places are comparable: U.S. Census Bureau, Annual estimates of the resident population for the United States, states and counties, 1 July (Population Estimates Program). Retrieved 2026-10-08.

Population: other rankings

Counties in Idaho: more rankings