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List of Cities and Counties in Idaho
Discover Idaho population facts easily with our list of counties and cities. Find out how many people live in each area, from big cities to small towns, and see how Idaho’s population is spread out across the state.
Idaho Counties by Population
A county is an administrative subdivision of a US state or territory. As of 2022, Idaho is divided into 44 counties.
The average population of Idaho counties is 43,203; Ada County is the most populous (511,931) and Clark County is the least (792). The average land area is 1882 sq mi. The largest county is Idaho County (8,485 sq mi) and the smallest is Payette County (408 sq mi).
read about the Population of Idaho
# | County | Population 2021 | Area (sq. mi.) | Density (people/sq. mi) |
1 | Ada County | 511,931 | 1,055 | 485.24 |
2 | Canyon County | 243,115 | 590 | 412.06 |
3 | Kootenai County | 179,789 | 1,245 | 144.41 |
4 | Bonneville County | 127,930 | 1,869 | 68.45 |
5 | Twin Falls County | 92,243 | 1,925 | 47.92 |
6 | Bannock County | 88,263 | 1,113 | 79.30 |
7 | Madison County | 53,881 | 472 | 114.15 |
8 | Bonner County | 49,491 | 1,738 | 28.48 |
9 | Bingham County | 48,876 | 2,095 | 23.33 |
10 | Nez Perce County | 42,454 | 849 | 50.00 |
11 | Latah County | 40,313 | 1,077 | 37.43 |
12 | Jefferson County | 32,202 | 1,095 | 29.41 |
13 | Elmore County | 28,827 | 3,078 | 9.37 |
14 | Payette County | 26,350 | 408 | 64.58 |
15 | Cassia County | 25,164 | 2,567 | 9.80 |
16 | Blaine County | 24,766 | 2,645 | 9.36 |
17 | Jerome County | 24,662 | 600 | 41.10 |
18 | Minidoka County | 21,955 | 760 | 28.89 |
19 | Gem County | 19,792 | 563 | 35.15 |
20 | Idaho County | 17,040 | 8,485 | 2.01 |
21 | Gooding County | 15,772 | 731 | 21.58 |
22 | Franklin County | 14,666 | 666 | 22.02 |
23 | Shoshone County | 13,612 | 2,634 | 5.17 |
24 | Fremont County | 13,592 | 1,867 | 7.28 |
25 | Boundary County | 12,561 | 1,269 | 9.90 |
26 | Owyhee County | 12,336 | 7,678 | 1.61 |
27 | Teton County | 12,267 | 450 | 27.26 |
28 | Valley County | 12,241 | 3,733 | 3.28 |
29 | Washington County | 10,898 | 1,456 | 7.48 |
30 | Benewah County | 9,931 | 776 | 12.80 |
31 | Clearwater County | 8,895 | 2,462 | 3.61 |
32 | Lemhi County | 8,162 | 4,564 | 1.79 |
33 | Boise County | 8,094 | 1,902 | 4.26 |
34 | Power County | 7,950 | 1,406 | 5.65 |
35 | Caribou County | 7,111 | 1,766 | 4.03 |
36 | Bear Lake County | 6,545 | 971 | 6.74 |
37 | Lincoln County | 5,282 | 1,206 | 4.38 |
38 | Adams County | 4,625 | 1,365 | 3.39 |
39 | Oneida County | 4,611 | 1,200 | 3.84 |
40 | Custer County | 4,428 | 4,926 | 0.90 |
41 | Lewis County | 3,715 | 479 | 7.76 |
42 | Butte County | 2,654 | 2,233 | 1.19 |
43 | Camas County | 1,139 | 1,077 | 1.06 |
44 | Clark County | 792 | 1,765 | 0.45 |
Source: US Census report 2021
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Top Cities in Idaho by population
Idaho is divided into 44 counties and contains 201 cities. The largest and most populated city in Idaho is State Capital, Boise (235,684). It’s followed by Meridian (117,635) and Nampa (100,200).
Let’s have a look at the top cities in Idaho by population
# | City | Population |
1 | Boise City | 235,684 |
2 | Meridian | 117,635 |
3 | Nampa | 100,200 |
4 | Idaho Falls | 64,818 |
5 | Caldwell | 59,996 |
6 | Pocatello | 56,320 |
7 | Coeur d’Alene | 54,628 |
8 | Twin Falls | 51,807 |
9 | Rexburg | 39,409 |
10 | Post-Falls | 38,485 |
Source: US Census 2020
Most Populous Counties in Idaho
The most populous county in Idaho is Ada County with 511,931 residents. It was followed by Canyon County (243,115) and Kootenai County (179,789)
Let’s have a look at the Top 10 most populous counties
# | County | Population 2021 |
1 | Ada County | 511,931 |
2 | Canyon County | 243,115 |
3 | Kootenai County | 179,789 |
4 | Bonneville County | 127,930 |
5 | Twin Falls County | 92,243 |
6 | Bannock County | 88,263 |
7 | Madison County | 53,881 |
8 | Bonner County | 49,491 |
9 | Bingham County | 48,876 |
10 | Nez Perce County | 42,454 |
Least Populated Idaho County
The least populous county is Clark County with 792 residents, it’s followed by Camas County and Butte County.
Let’s have a look at 5 least populated counties in Idaho
# | County | Population 2021 |
1 | Clark County | 792 |
2 | Camas County | 1,139 |
3 | Butte County | 2,654 |
4 | Lewis County | 3,715 |
5 | Custer County | 4,428 |
source: US Census 2021
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Largest counties in Idaho by area
The Largest county by Land Area in Idaho is Idaho County with an area of 8,485 sq. miles. Owyhee County with an area of 7,678 sq. mi. comes next followed by Custer County (4,926 sq. mi.)
Let’s have a look at the Top 10 counties by Area
# | County | Area (sq. mi.) |
1 | Idaho County | 8,485 |
2 | Owyhee County | 7,678 |
3 | Custer County | 4,926 |
4 | Lemhi County | 4,564 |
5 | Valley County | 3,733 |
6 | Elmore County | 3,078 |
7 | Blaine County | 2,645 |
8 | Shoshone County | 2,634 |
9 | Cassia County | 2,567 |
10 | Clearwater County | 2,462 |
Smallest County in Idaho by area
The smallest county by area in Idaho is Payette County with an area of 408 square miles.
# | County | Area (sq. mi.) |
1 | Payette County | 408 |
2 | Teton County | 450 |
3 | Madison County | 472 |
4 | Lewis County | 479 |
5 | Gem County | 563 |
source: US Census report 2021
Most Densely populated Counties in Idaho
The most densely populated county in Idaho is Ada County, with 485 people per sq. mi. Next comes Canyon County with 412 people per sq. mi. followed by Kootenai County (144/ sq.mi)
Let’s have a look at the Top 10 densely populated counties
# | County | Density (people/sq. mi) |
1 | Ada County | 485.24 |
2 | Canyon County | 412.06 |
3 | Kootenai County | 144.41 |
4 | Madison County | 114.15 |
5 | Bannock County | 79.30 |
6 | Bonneville County | 68.45 |
7 | Payette County | 64.58 |
8 | Nez Perce County | 50.00 |
9 | Twin Falls County | 47.92 |
10 | Jerome County | 41.10 |
Least Densely Populated County in Idaho
Clark County with a population density of just 0.45 people per sq. miles is the least densely populated county in Idaho
# | County | Density (people/sq. mi) |
1 | Clark County | 0.45 |
2 | Custer County | 0.90 |
3 | Camas County | 1.06 |
4 | Butte County | 1.19 |
5 | Owyhee County | 1.61 |