Arizona Counties by Population (2025)
2025 Pop.
500K
1M
1.5M
2M
2.5M
3M
3.5M
4M
4.5M
Top 5 Most Populous Counties
4,730,567
1,091,719
541,329
254,527
229,157
15 Counties
| County | 2025 Pop. ↓ | Area (mi²) | Density | Change (2020) |
|---|---|---|---|---|
| Maricopa County | 4,730,567 | 9.2K | 514 | 6.41% |
| Pima County | 1,091,719 | 9.2K | 119 | 4.45% |
| Pinal County | 541,329 | 5.4K | 101 | 25.83% |
| Yavapai County | 254,527 | 8.1K | 31 | 7.29% |
| Mohave County | 229,157 | 13.3K | 17 | 7% |
| Yuma County | 225,172 | 5.5K | 41 | 9.48% |
| Coconino County | 145,388 | 18.6K | 8 | 0.14% |
| Cochise County | 126,665 | 6.2K | 20 | 0.9% |
| Navajo County | 109,751 | 9.9K | 11 | 2.79% |
| Apache County | 64,479 | 11.2K | 6 | -2.18% |
| Gila County | 54,086 | 4.8K | 11 | 1.37% |
| Santa Cruz County | 51,369 | 1.2K | 42 | 7.66% |
| Graham County | 40,923 | 4.6K | 9 | 5.94% |
| La Paz County | 17,172 | 4.5K | 4 | 3.61% |
| Greenlee County | 9,437 | 1.8K | 5 | -0.99% |
Overview of Arizona Counties
There are 15 counties in Arizona.
Maricopa County is the largest county in the state, with a population of 4,730,567. The most recent census shows that its population has increased by 0.06% 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 : 1,091,719
- Pinal County : 541,329
Arizona Counties with the Fewest Residents
The smallest county in Arizona is Greenlee County , with a population of just 9,437. This total represents a decrease of 0.0% since the last census count was performed.
Other small counties include:
- La Paz County : 17,172
- Graham County : 40,923
- Santa Cruz County : 51,369
Arizona Counties with Rapid Growth
Pinal County , with its sizeable population of 541,329, has shown the largest population growth, with an increase of 0.3% since the last census.
On the other hand, Apache County has had the largest decrease in population, with its 64,479 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)