Alphabetical List of All Counties in Idaho


There are a total of 44 counties in the state of Idaho. Among them, Owyhee County is the oldest one (established in 1863) while Caribou County is the youngest (established in 1919).  With population of 392,365, Ada County is the most populated. The biggest county by land area is Idaho County (21,976 km2) and the smallest is Payette County (1,057 km2). Below please see all Idaho counties which are listed in alphabetical order.

  1. Ada County, ID
  2. Adams County, ID
  3. Bannock County, ID
  4. Bear Lake County, ID
  5. Benewah County, ID
  6. Bingham County, ID
  7. Blaine County, ID
  8. Boise County, ID
  9. Bonner County, ID
  10. Bonneville County, ID
  11. Boundary County, ID
  12. Butte County, ID
  13. Camas County, ID
  14. Canyon County, ID
  15. Caribou County, ID
  16. Cassia County, ID
  17. Clark County, ID
  18. Clearwater County, ID
  19. Custer County, ID
  20. Elmore County, ID
  21. Franklin County, ID
  22. Fremont County, ID
  23. Gem County, ID
  24. Gooding County, ID
  25. Idaho County, ID
  26. Jefferson County, ID
  27. Jerome County, ID
  28. Kootenai County, ID
  29. Latah County, ID
  30. Lemhi County, ID
  31. Lewis County, ID
  32. Lincoln County, ID
  33. Madison County, ID
  34. Minidoka County, ID
  35. Nez Perce County, ID
  36. Oneida County, ID
  37. Owyhee County, ID
  38. Payette County, ID
  39. Power County, ID
  40. Shoshone County, ID
  41. Teton County, ID
  42. Twin Falls County, ID
  43. Valley County, ID
  44. Washington County, ID