List of counties in Arizona

There are 15 counties in the U.S. state of Arizona. Four counties (Mohave, Pima, Yavapai and Yuma) were formed in 1864 in the Arizona Territory in 1862. All but La Paz County were formed by the time Arizona became a State in 1912. There is also one county, Pah-Ute County, Arizona that was formed in 1865 from Mohave County and returned in 1871.

The names of many of the counties honor the state's Native American past. Nine of the fifteen counties are named after native groups that live in parts of what is now Arizona. Three of the other counties have Spanish names from the language of the early Hispanic explorers of Arizona. Another county, Graham County, is named for a physical feature, Mount Graham. Greenlee County is named after one of the state's early pioneers.

Arizona's United States postal abbreviations is AZ and its FIPS code is 04.

Alphabetical listing

County	FIPS code	County seat	Established	Formed from	Meaning of name	Population	Area	Map
Apache County	001	St. Johns	1879	Part of Yavapai County.	The Apache Native American people, who live in northeastern Arizona.	7004699800000000000♠69,980	7004112180000000000♠11,218 sq mi (7004290540000000000♠29,054 km2)
Cochise County	003	Bisbee	1881	Part of Pima County.	Cochise, the Apache Native American leader.	7005127866000000000♠127,866	7003621900000000000♠6,219 sq mi (7004161070000000000♠16,107 km2)
Coconino County	005	Flagstaff	1891	Part of Yavapai County.	Coconino Native American people, a Hopi designation for Havasupai and Yavapai people.	7005223214000000000♠223,214	7004186610000000000♠18,661 sq mi (7004483320000000000♠48,332 km2)
Gila County	007	Globe	1881	Parts of Maricopa County and Pinal County.	Gila River, a river that flows through Arizona, whose name comes from a Pima Indian word.	7004519940000000000♠51,994	7003479600000000000♠4,796 sq mi (7004124220000000000♠12,422 km2)
Graham County	009	Safford	1881	Parts of Apache County and Pima County.	Mount Graham, a mountain in Arizona's Pinaleno Mountains.	7004347690000000000♠34,769	7003464100000000000♠4,641 sq mi (7004120200000000000♠12,020 km2)
Greenlee County	011	Clifton	1909	Part of Graham County.	Mason Greenlee, a pioneer prospector in the area who died in 1903.	7003775400000000000♠7,754	7003184800000000000♠1,848 sq mi (7003478600000000000♠4,786 km2)
La Paz County	012	Parker	1983	Part of Yuma County.	La Paz, Arizona, a historic boomtown on the Colorado River. La paz means the peace in Spanish.	7004201720000000000♠20,172	7003451300000000000♠4,513 sq mi (7004116890000000000♠11,689 km2)
Maricopa County	013	Phoenix	1871	Parts of Pima County and Yavapai County.	Maricopa Native American people.	7006399018100000000♠3,990,181	7003922400000000000♠9,224 sq mi (7004238900000000000♠23,890 km2)
Mohave County	015	Kingman	1864	One of the original 4 counties.	Mohave Indians, one of the Yuma tribes.	7005194944000000000♠194,944	7004134700000000000♠13,470 sq mi (7004348870000000000♠34,887 km2)
Navajo County	017	Holbrook	1895	Part of Apache County.	Navajo Native American people.	7005111273000000000♠111,273	7003995900000000000♠9,959 sq mi (7004257940000000000♠25,794 km2)
Pima County	019	Tucson	1864	One of the original 4 counties.	Pima Native American people, called in their own language Akimel O'odham (river people).	7006100323500000000♠1,003,235	7003918900000000000♠9,189 sq mi (7004237990000000000♠23,799 km2)
Pinal County	021	Florence	1875	Parts of Maricopa and Pima counties.	Pinal Mountains (named from the Spanish for stand of pines) and the Pinal Native American people (a band of Coyotero Apaches) who lived there.	7005324962000000000♠324,962	7003537400000000000♠5,374 sq mi (7004139190000000000♠13,919 km2)
Santa Cruz County	023	Nogales	1899	Parts of Cochise and Pima counties.	Santa Cruz River, a small river that flows through Arizona.	7004428450000000000♠42,845	7003123800000000000♠1,238 sq mi (7003320600000000000♠3,206 km2)
Yavapai County	025	Prescott	1864	One of the original 4 counties.	Yavapaim Native American people, who are from central Arizona	7005212635000000000♠212,635	7003812800000000000♠8,128 sq mi (7004210510000000000♠21,051 km2)
Yuma County	027	Yuma	1864	One of the original 4 counties.	Yuma Indians, today called the Quechan.	7005190557000000000♠190,557	7003551900000000000♠5,519 sq mi (7004142940000000000♠14,294 km2)