PlainCities

Counties · Idaho

Counties of Idaho

Idaho has 44 counties. Ada County is the largest with 546,141 residents in 2025. 43 of the 44 gained residents between 2020 and 2025 by the Census Bureau's estimates.

What counties are in Idaho?

Sorted by the 2025 population estimate; sort by any column.

Counties of Idaho: 2025 estimate, change since 2020, ACS 2020-2024 5-year estimates
Ada County546,141+10.3%8129$91,502$512,300
Canyon County275,123+19.0%954$76,488$390,000
Kootenai County191,864+12.0%1639$81,861$518,700
Bonneville County135,771+9.5%824$79,068$368,800
Twin Falls County97,539+8.3%817$67,409$337,900
Bannock County91,591+5.2%924$66,499$300,700
Madison County55,172+4.3%211$60,160$414,800
Bonner County54,420+15.5%1216$66,979$487,900
Bingham County51,153+6.6%1010$77,878$293,300
Nez Perce County42,905+1.9%510$72,599$334,700
Latah County41,842+5.9%119$65,424$368,600
Jefferson County35,297+14.3%76$86,679$408,400
Elmore County29,465+2.8%47$65,359$316,500
Payette County27,824+9.6%35$67,673$341,800
Cassia County26,397+6.9%56$70,830$284,600
Jerome County26,362+8.7%36$71,724$271,800
Blaine County25,517+5.1%68$92,566$735,300
Minidoka County22,911+6.1%65$70,377$262,600
Gem County21,773+13.8%24$64,605$428,700
Idaho County17,874+8.0%96$66,325$310,200
Gooding County16,446+5.4%44$63,559$250,900
Franklin County15,889+11.9%62$71,950$372,600
Fremont County14,208+6.1%84$72,683$314,200
Shoshone County14,130+7.3%83$55,527$267,400
Boundary County13,997+16.1%22$67,237$410,500
Teton County13,254+13.9%37$99,805$690,500
Valley County12,831+9.3%54$76,078$657,000
Owyhee County12,661+6.3%53$64,406$359,800
Washington County11,583+10.4%33$54,000$278,100
Benewah County10,508+10.2%62$59,794$293,500
Clearwater County9,118+4.4%43$60,000$268,200
Boise County8,545+12.3%83$78,774$476,100
Lemhi County8,474+6.3%23$53,202$326,100
Power County8,246+4.7%42$61,146$212,900
Caribou County7,252+3.2%32$68,782$241,500
Bear Lake County6,727+5.7%62$75,260$275,000
Lincoln County5,603+9.2%31$71,453$255,600
Oneida County5,085+11.4%11$74,954$272,000
Adams County5,013+14.5%22$61,808$376,500
Custer County4,636+8.4%51$67,574$381,700
Lewis County3,704+4.8%53$51,615$225,300
Butte County2,783+8.2%31$53,015$217,600
Camas County1,316+22.8%11$57,955$304,000
Clark County783−0.6%21$55,208$216,900

Source: PEP Vintage 2025 (CO-EST2025); American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) · Census population estimates

How these figures are made: methodology and release checks · reading a margin of error · every state · corrections