De Amerikaanse staat Idaho is onderverdeeld in 44 county's.
right|400px|thumb|County's van Idaho
CountyInwonersU.S. Census Bureau: Annual Estimates of the Population for Counties: April 1, 2000 to July 1, 20071 juli 2007HoofdplaatsInwonersU.S. Census Bureau: Population Estimates for All Places: 2000 to 20071 juli 2007Ada373.406Boise202.832Adams3546Council691Bannock79.925Pocatello54.572Bear Lake5863Paris494Benewah9243St. Maries2624Bingham43.466Blackfoot10.867Blaine21.560Hailey7844Boise7571Idaho City478Bonner41.050Sandpoint8216Bonneville96.545Idaho Falls53.279Boundary10.872Bonners Ferry2635Butte2771Arco982Camas1102Fairfield410Canyon179.381Caldwell39.889Caribou6862Soda Springs3098Cassia20.960Burley8984Clark906Dubois613Clearwater8231Orofino3073Custer4166Challis873Elmore28.856Mountain Home12.236Franklin12.203Preston4947Fremont12.517St. Anthony3401Gem16.496Emmett6341Gooding14.250Gooding3208Idaho15.345Grangeville3091Jefferson22.851Rigby3312Jerome20.066Jerome8827Kootenai134.442Coeur d'Alene42.267Latah36.299Moscow23.223Lemhi7717Salmon2961Lewis3581Nezperce488Lincoln4497Shoshone1565Madison36.647Rexburg27.575Minidoka18.564Rupert5075Nez Perce38.932Lewiston31.794Oneida4106Malad City2065Owyhee10.835Murphy1532Payette22.751Payette7629Power7684American Falls4081Shoshone12.838Wallace867Teton8349Driggs1291Twin Falls73.058Twin Falls41.510Valley8945Cascade1004Washington10.147Weiser5330
Idaho