Ada County Seal
A A A
Home > About Ada County

About Ada County

Ada County is the largest county by population in Idaho, home to approximately 25% of the state’s residents. Ada County is more than one thousand square miles of high desert beauty, peppered with foothills and a glistening river that winds through urban and rural landscapes. Ada County includes Idaho’s capital city Boise and it is home to five other distinct municipalities: Star, Eagle, Meridian, Garden City, and Kuna.

The county as a whole is known for a rich agricultural heritage and open spaces for recreation. Thousands of acres of Open Space make the county an exceptional place to live and work. It is also the state’s commerce and industry hub, and boasts a vibrant and diverse arts scene. EXPO Idaho in Ada County hosts the annual Western Idaho Fair, one of the biggest events each year in Southwest Idaho. While the county is projected to be just shy of 700,000 by 2040, protecting Ada County’s quality of life and unique heritage in a fiscally responsible manner remains paramount for leaders across the county.

Interesting Ada County Facts:

  • Ada County was established on December 22, 1864
  • Ada County was named after Ada Riggs, the daughter of Idaho Territorial Legislator H.C. Riggs, one of the founders of Boise
  • The surface area of Ada County is 1054.99 square miles
  • Average commute time to work in Ada County is under 20 minutes
  • Learn more on Ada County’s current population, demographics and other quick facts from the U.S. Census Bureau
County Map of Cities in Ada County

Ada County Cities