Ada County Flag

Ada County

State:
Idaho
County Seat:
Boise

Ada County's estimated 2025 population is 536,011 with a growth rate of 1.07% in the past year according to the most recent United States census data. Ada County is the 1st largest county in Idaho. The 2010 population was 393,369 and has seen a growth of 36.26% since that time.

536,011
Total Population
510
Population Density (mi²)
1
Population Rank (State)
5.7K 1.07%
Annual Population Growth

Ada County Population

Demographics

Economics and Income Statistics