Skip to main content
Population Review

Census ACS 2023 · 44 counties

Largest Counties in Idaho

Idaho has 44 counties with Census data available. The largest is Ada County with a population of 508,052. County-level data is important because counties are the primary unit of local government in most states, responsible for courts, elections, public health, and infrastructure. Population distribution across counties reveals where growth is concentrated and where rural decline may be occurring.

Source: Census ACS 2023 5-Year Estimates

#CountyPopulationMedian Income
1Washington County10,866$53,608
2Valley County12,136$76,125
3Twin Falls County92,121$65,338
4Teton County12,101$90,740
5Shoshone County13,580$49,975
6Power County8,018$59,760
7Payette County26,190$65,723
8Owyhee County12,284$59,773
9Oneida County4,681$72,563
10Nez Perce County42,477$71,466
11Minidoka County21,922$70,060
12Madison County53,578$58,259
13Lincoln County5,276$66,038
14Lewis County3,649$49,643
15Lemhi County8,166$52,057
16Latah County40,315$65,179
17Kootenai County177,736$77,034
18Jerome County24,788$69,338
19Jefferson County32,234$82,952
20Idaho County17,120$60,975
21Gooding County15,740$62,395
22Gem County19,854$66,245
23Fremont County13,701$72,767
24Franklin County14,715$65,991
25Elmore County29,046$58,976
26Custer County4,411$56,957
27Clearwater County8,921$57,961
28Clark County776$52,083
29Cassia County25,165$67,042
30Caribou County7,118$66,653
31Canyon County242,405$72,355
32Camas County1,155$55,536
33Butte County2,654$43,281
34Boundary County12,695$62,438
35Bonneville County127,056$76,646
36Bonner County49,456$65,168
37Boise County8,045$77,349
38Blaine County24,579$84,470
39Bingham County48,993$76,842
40Benewah County9,913$56,553
41Bear Lake County6,552$67,304
42Bannock County88,457$64,080
43Adams County4,599$59,286
44Ada County508,052$88,907

More Rankings for Idaho

Largest CitiesRichest CitiesMost Expensive CitiesYoungest CitiesMost Educated CitiesCities With Highest RentRichest Counties

Frequently Asked Questions

Ada County is the #1 ranked county in Idaho by population, with a value of 508,052 according to Census ACS 2023 data.

Idaho has 44 counties tracked in Census ACS 2023 data.

All data comes from the American Community Survey (ACS) 2023 5-Year estimates by the US Census Bureau.

Sources: US Census Bureau ACS 2023 5-Year Estimates

Data from the American Community Survey 2023 5-Year estimates. Covers all counties in Idaho.