Hover/click a county for data.

Population of Counties in Idaho (2024)

Download Table Data

Enter your email below, and you'll receive this table's data in your inbox momentarily.

2024 Population
Growth Since 2020
Area (mi²)
Density (/mi²)
Ada County530,3426.43%1.1K504Ada County location
Canyon County264,45613.49%587451Canyon County location
Kootenai County186,7308.07%1.2K151Kootenai County location
Bonneville County133,1896.78%1.9K71Bonneville County location
Twin Falls County96,4916.77%1.9K50Twin Falls County location
Bannock County91,1754.47%1.1K82Bannock County location
Madison County54,1362.28%469115Madison County location
Bonner County53,68713.26%1.7K31Bonner County location
Bingham County50,8175.66%2.1K24Bingham County location
Nez Perce County43,0652.18%84851Nez Perce County location
Latah County41,6785.15%1.1K39Latah County location
Jefferson County35,06012.81%1.1K32Jefferson County location
Elmore County30,0574.84%3.1K10Elmore County location
Payette County27,6297.97%40768Payette County location
Cassia County25,7483.99%2.6K10Cassia County location
Jerome County25,7145.95%59843Jerome County location
Blaine County25,1813.42%2.6K10Blaine County location
Minidoka County22,7525%75730Minidoka County location
Gem County21,68812.54%56039Gem County location
Idaho County18,1439.33%8.5K2Idaho County location
Gooding County16,2433.8%72922Gooding County location
Franklin County15,81810.75%66324Franklin County location
Fremont County14,3757.12%1.9K8Fremont County location
Shoshone County14,1176.96%2.6K5Shoshone County location
Boundary County13,84214.03%1.3K11Boundary County location
Valley County12,8388.41%3.7K4Valley County location
Owyhee County12,7996.69%7.7K2Owyhee County location
Teton County12,5797.19%44928Teton County location
Washington County11,70310.84%1.5K8Washington County location
Benewah County10,4479.1%77713Benewah County location
Clearwater County9,3937.35%2.5K4Clearwater County location
Boise County8,67413.18%1.9K5Boise County location
Lemhi County8,5987.99%4.6K2Lemhi County location
Power County8,3706.23%1.4K6Power County location
Caribou County7,2383.21%1.8K4Caribou County location
Bear Lake County6,8026.83%9767Bear Lake County location
Lincoln County5,5157.42%1.2K5Lincoln County location
Oneida County5,16613.14%1.2K4Oneida County location
Adams County5,01513.26%1.4K4Adams County location
Custer County4,5286.02%4.9K1Custer County location
Lewis County3,7536.41%4798Lewis County location
Butte County2,8189.06%2.2K1Butte County location
Camas County1,29519.46%1.1K1Camas County location
Clark County7920%1.8K0.45Clark County location
showing: 44 rows

There are 44 counties in Idaho. As of 2019, Idaho's most populous county is Ada County, home of Boise, with 469,966 residents. This represents a population growth of 19.48% since the 2010 census. Ada County is followed by Canyon County (223,499), Kootenai County (161,505), and Bonneville County (116,854). These are the only counties in Idaho with a population exceeding 100,000. Of these counties, Ada County experienced the highest population growth.

Idaho Counties with Fewest Residents

The least populated county in Idaho is Clark County with a population of 852 in 2019, down 13.06% since the last census. There are 15 counties in Idaho with fewer than 10,000 residents. Other small counties in Idaho are Camas County (1,127), Butte County (2,611), Lewis County (3,861), Adams County (4,250), Custer County (4,280), and Oneida County (4,488). Of these counties, Clark County experienced the most dramatic decline with a population growth rate of -13.06%. Adams County experienced the highest growth with a population that grew by 7.27% since the census.

Idaho Counties with Rapid Growth

Ada County, the largest county in Idaho, also experienced the most rapid growth over the last decade, climbing 19.48% to 469,966 people. Other cities that have experienced rapid growth include Canyon County (18.03%), Kootenai County (16.31%), Teton County (14.67%), Valley County (12.80%), and Jefferson County (12.27%). Only 8 counties in Idaho experienced negative growth since the census. The most dramatic decline was in Clark County, which dropped 13.06%, followed by Butte County at -10.43%. No other county experienced decline of more than 2%.

Population of Counties in Idaho (2024)

Lists of Counties in all States

  1. Idaho Department of Labor
  2. US Census State Population Estimates - Most recent state estimates from the Census Bureau's Population Estimates Program
  3. US Census County Population Estimates - Most recent county estimates from the Census Bureau's Population Estimates Program
  4. American Community Survey (2009 - 2013)
  5. Census QuickFacts
  6. Historical Populations of States and Counties (1790 - 1990)