County facts · Land area · October 21, 2026
Largest Counties in Arizona by Area and Population
The largest Arizona counties by land area and by 2023 population, plus the smallest, county seats and a link to each official parcel map.
Looking for the largest counties in Arizona? Arizona has 15 counties covering about 113,653 square miles of land, based on the Census Bureau's 2020 Gazetteer. The largest by land area is Coconino County, at about 18,616 square miles, roughly 15 times the size of the smallest, Santa Cruz County (1,236 sq mi). Measured by people instead, the largest is Maricopa County, with about 4,585,871 residents in the Census Bureau's July 1, 2023 estimate.
Each table below links the county's Platbookmapper page and its official parcel viewer, so you can go straight from the numbers to the property lines.
Arizona counties at a glance
- Counties: 15
- Land area: about 113,653 sq mi, plus about 332 sq mi of water inside county lines
- Residents, 2023 estimates: about 7,431,344, or about 65 people per square mile of land
- Median county land area: about 6,210 sq mi
- With a verified public parcel viewer in our directory: 14 of 15
The 10 largest Arizona counties by land area
| # | County | Seat | Land (sq mi) | 2023 pop. | People per sq mi | Parcel viewer |
|---|---|---|---|---|---|---|
| 1 | Coconino County | Flagstaff | 18,616 | 144,472 | 7.8 | ArcGIS Experience Builder |
| 2 | Mohave County | Kingman | 13,332 | 223,682 | 17 | county web map |
| 3 | Apache County | St. Johns | 11,198 | 65,036 | 5.8 | county web map |
| 4 | Navajo County | Holbrook | 9,949 | 109,175 | 11 | county web map |
| 5 | Maricopa County | Phoenix | 9,202 | 4,585,871 | 498 | county web map |
| 6 | Pima County | Tucson | 9,189 | 1,063,162 | 116 | county web map |
| 7 | Yavapai County | Prescott | 8,123 | 249,081 | 31 | ArcGIS Experience Builder |
| 8 | Cochise County | Bisbee | 6,210 | 124,640 | 20 | ArcGIS Web AppBuilder |
| 9 | Yuma County | Yuma | 5,514 | 213,221 | 39 | ArcGIS Experience Builder |
| 10 | Pinal County | Florence | 5,366 | 484,239 | 90 | ArcGIS Experience Builder |
Together these 10 cover about 85% of Arizona's land area and hold about 98% of its residents.
The 10 most populous Arizona counties
| # | County | Seat | 2023 pop. | Land (sq mi) | Parcel viewer |
|---|---|---|---|---|---|
| 1 | Maricopa County | Phoenix | 4,585,871 | 9,202 | county web map |
| 2 | Pima County | Tucson | 1,063,162 | 9,189 | county web map |
| 3 | Pinal County | Florence | 484,239 | 5,366 | ArcGIS Experience Builder |
| 4 | Yavapai County | Prescott | 249,081 | 8,123 | ArcGIS Experience Builder |
| 5 | Mohave County | Kingman | 223,682 | 13,332 | county web map |
| 6 | Yuma County | Yuma | 213,221 | 5,514 | ArcGIS Experience Builder |
| 7 | Coconino County | Flagstaff | 144,472 | 18,616 | ArcGIS Experience Builder |
| 8 | Cochise County | Bisbee | 124,640 | 6,210 | ArcGIS Web AppBuilder |
| 9 | Navajo County | Holbrook | 109,175 | 9,949 | county web map |
| 10 | Apache County | St. Johns | 65,036 | 11,198 | county web map |
These 10 hold about 98% of Arizona's residents in the 2023 estimates.
The 5 smallest Arizona counties by land area
| County | Seat | Land (sq mi) | 2023 pop. | Parcel viewer |
|---|---|---|---|---|
| Santa Cruz County | Nogales | 1,236 | 49,158 | ArcGIS Map Viewer |
| Greenlee County | Clifton | 1,842 | 9,369 | no verified public viewer listed yet |
| La Paz County | Parker | 4,497 | 16,710 | ArcGIS Experience Builder |
| Graham County | Safford | 4,622 | 39,525 | ArcGIS Experience Builder |
| Gila County | Globe | 4,757 | 54,003 | ArcGIS Web AppBuilder |
Most and least crowded
- Most people per square mile: Maricopa County, about 498 (then Pima County, 116, and Pinal County, 90)
- Fewest people per square mile: La Paz County, about 3.7 (then Greenlee County, 5.1, and Apache County, 5.8)
Counties with the most water
The Census Bureau reports water separately from land. It counts lakes, reservoirs, rivers and, for coastal and Great Lakes counties, the water inside the county boundary.
- Mohave County: about 129 sq mi of water, 1% of its total area
- Coconino County: about 45 sq mi of water, 0% of its total area
- Gila County: about 37 sq mi of water, 1% of its total area
Using these numbers in a land search
- Land area is not parcel count. A large rural county can hold fewer parcels than a small suburban one, so size alone says little about how busy its parcel map is.
- Search, don't scroll. In a big county, type an address, owner name or parcel number into the viewer's search box, where it has one, instead of panning across the map.
- Records follow the county line. Deeds, plats and tax bills are kept by the county where the parcel sits, so a tract that crosses a county line usually has a parcel number in each county.
- Rounded figures. Land and water areas are rounded to whole square miles. People per square mile is the 2023 estimate divided by land area.
Related guides
More: All Arizona counties on Platbookmapper
Sources
- U.S. Census Bureau Gazetteer files, 2020 county land and water area.
- U.S. Census Bureau, Population Estimates Program, county totals, Vintage 2023 (July 1, 2023 estimates)
- Platbookmapper county GIS directory (live data file behind our county pages, pulled October 21, 2026) for each county's official parcel viewer.
- County seats: Wikidata (county seat property), cross-checked against Census place names.