Camas County is a county in the southern portion of the U.S. state of Idaho. The county seat and largest city is Fairfield. The county was established 107 years ago in 1917 by the Idaho Legislature with a partition of Blaine County on February 6. It is named for the camas root, or Camassia, a lily-like plant with an edible bulb found in the region, that Native Americans and settlers used as a food source. As of the 2020 census, the population was 1,077, making it the second-least populous county in the state, after Clark County.

Fairfield is the county seat of and the only village in Camas County, Idaho. The population was 410 at the time of 2010 census, nearly half of the rural county's population.