Arizona Counties by Population (2025)
Top 5 Most Populous Counties
15 Counties
| County | 2025 Pop. ↓ | Area (mi²) | Density | Change (2020) |
|---|---|---|---|---|
| Maricopa County | 4,645,947 | 9,202 | 505 | 4.52% |
| Pima County | 1,074,534 | 9,189 | 117 | 2.81% |
| Pinal County | 522,643 | 5,367 | 97 | 21.49% |
| Yavapai County | 254,783 | 8,123 | 31 | 7.41% |
| Mohave County | 229,236 | 13,332 | 17 | 7.03% |
| Yuma County | 221,915 | 5,514 | 40 | 7.9% |
| Coconino County | 144,970 | 18,616 | 8 | -0.15% |
| Cochise County | 122,946 | 6,210 | 20 | -2.06% |
| Navajo County | 109,925 | 9,949 | 11 | 2.96% |
| Apache County | 64,042 | 11,198 | 6 | -2.84% |
| Gila County | 54,165 | 4,758 | 11 | 1.53% |
| Santa Cruz County | 50,114 | 1,236 | 41 | 5.03% |
| Graham County | 40,931 | 4,622 | 9 | 5.91% |
| La Paz County | 17,060 | 4,497 | 4 | 2.96% |
| Greenlee County | 9,453 | 1,843 | 5 | -0.79% |
Overview of Arizona Counties
There are 15 counties in Arizona.
Maricopa County is the largest county in the state, with a population of 4,645,947. The most recent census shows that its population has increased by 0.05% since the previous census.
A number of other Arizona counties also boast relatively large populations for their state, though not able to match the density of Maricopa County:
- Pima County : 1,074,534
- Pinal County : 522,643
Arizona Counties with the Fewest Residents
The smallest county in Arizona is Greenlee County, with a population of just 9,453. This total represents a decrease of 0.0% since the last census count was performed.
Other small counties include:
- La Paz County : 17,060
- Graham County : 40,931
- Santa Cruz County : 50,114
Arizona Counties with Rapid Growth
Pinal County, with its sizeable population of 522,643, has shown the largest population growth, with an increase of 0.2% since the last census.
On the other hand, Apache County has had the largest decrease in population, with its 64,042 current residents totalling 0.0% less than the previous census.
Sources
- US Census State Population Estimates - Most recent state estimates from the Census Bureau's Population Estimates Program
- US Census County Population Estimates - Most recent county estimates from the Census Bureau's Population Estimates Program
- American Community Survey (2009 - 2013)
- Census QuickFacts
- Historical Populations of States and Counties (1790 - 1990)