Data / Rankings / Population / Counties in Arizona

Counties in Arizona by population

Maricopa County had the highest population of 15 counties in 2020, at 4.45 million. Greenlee County had the lowest, at 9,531. The median was 125,527 and the figure for Arizona was 7.19 million. Source: the U.S. Census Bureau.

Highest4,445,025Maricopa County
Lowest9,531Greenlee County
Median125,52715 counties
Arizona7,186,647History

All counties, 2020

CSVChart (SVG)

Maricopa CountyMaricopa County: 4,445,025 persons4,445,025Pima CountyPima County: 1,045,245 persons1,045,245Pinal CountyPinal County: 430,231 persons430,231Yavapai CountyYavapai County: 237,223 persons237,223Mohave CountyMohave County: 214,167 persons214,167Yuma CountyYuma County: 205,618 persons205,618Coconino CountyCoconino County: 145,182 persons145,182Cochise CountyCochise County: 125,527 persons125,527Navajo CountyNavajo County: 106,748 persons106,748Apache CountyApache County: 65,913 persons65,913Gila CountyGila County: 53,338 persons53,338Santa Cruz CountySanta Cruz County: 47,711 persons47,711Graham CountyGraham County: 38,626 persons38,626La Paz CountyLa Paz County: 16,562 persons16,562Greenlee CountyGreenlee County: 9,531 persons9,531
persons. Source: U.S. Census Bureau. Retrieved 2026-10-08.

Full ranking

RankCounties2020
persons
1Maricopa County4,445,025
2Pima County1,045,245
3Pinal County430,231
4Yavapai County237,223
5Mohave County214,167
6Yuma County205,618
7Coconino County145,182
8Cochise County125,527
9Navajo County106,748
10Apache County65,913
11Gila County53,338
12Santa Cruz County47,711
13Graham County38,626
14La Paz County16,562
15Greenlee County9,531

Other periods

About this ranking

Resident population. Spain and the EU: 1 January, with Spanish figures from the official municipal register (Padrón). United States: Census Bureau population estimates for 1 July. Other countries and the World: World Bank mid-year estimates, which count all residents regardless of legal status or citizenship.

For Denmark, Statistics Denmark counts the registered resident population on 1 January. Greenland and the Faroe Islands are excluded. The annual series selects the first-quarter reference date from FOLK1A. The World Bank series exists for every country, so use it (through compare) to rank countries on one basis.

Every value in the ranking comes from the same publisher and the same period, so the counties are compared on one definition. Equal values share a rank.

How to cite

U.S. Census Bureau. Annual estimates of the resident population for the United States, states and counties, 1 July (Population Estimates Program). https://www2.census.gov/programs-surveys/popest/datasets/2020-2025/. Retrieved 2026-10-08.

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Questions

Which county has the highest population?

Maricopa County, with 4.45 million in 2020, according to the U.S. Census Bureau.

Which county has the lowest population?

Greenlee County, with 9,531 in 2020.

Where does this ranking come from?

Every value comes from one source and one period, so the places are comparable: U.S. Census Bureau, Annual estimates of the resident population for the United States, states and counties, 1 July (Population Estimates Program). Retrieved 2026-10-08.

Population: other rankings

Counties in Arizona: more rankings