The cotton fields and deserts of Pinal County continue to be the hotspot for population growth in Arizona.
Despite containing only about 7% of Arizona’s population, four of the state's ten fastest-growing cities since 2020 were in the county located between Phoenix and Tucson, according to census data released Thursday. Meanwhile, many older communities in rural southern Arizona saw population declines.
Coolidge was Arizona’s fastest-growing city between July 2020 and July 2025, growing by over 48%. Maricopa, Casa Grande and Eloy were also in the top ten, all growing by more than 25%, with Maricopa seeing the largest net increase at over 19,000 new residents. Pinal County has been among the nation's fastest-growing counties for years.
Eloy is the smallest city in Pinal County. But Andrew Sutton, its mayor, said it’s perfectly positioned for the future.
“We have three exits on the I-10, we have a rail line, we are right smack in the middle, evenly, 50 miles between Tucson and Phoenix,” he said.
Eloy is expecting a $400 million investment from a new plastics recycling plant. The community recently received its first hospital, and Sutton said a new drywall manufacturing plant has attracted trucking businesses as well.
He said city plans have designated land near Interstate 10 and the railroad as industrial, with residential subdivisions further afield. He said a new sewer line under construction north of downtown Eloy is attracting residential developers interested in building subdivisions.
“We have a blank canvas right now to work with, and you only get that once in a city’s lifetime,” he said. “We want to be really sure of what we’re doing before we pull any triggers.”
Eloy is also home to several prisons and an ICE detention center. Inmates are counted in census data.
While Phoenix saw the largest net increase in residents — just over 53,000 — the city’s large size means they represented only about a 3% increase overall.
Marana is Pima County’s only city in the top ten, seeing a 24.5% increase thanks to almost 13,000 new residents.
Out of the cities that saw overall population declines, several were in southern Arizona, including Sierra Vista, Bisbee, Nogales, Willcox and Douglas.
Douglas has seen patchy population growth since a copper smelter, once a major employer, closed in the 1980s. Between July 2020 and July 2025, its population of roughly 16,000 shrunk by almost 500 people.
But its mayor said a port of entry set to open in 2029 is cause for optimism.
“It’s basically going to be an extension of the city out there,” Jose Grijalva said.
Grijalva hopes state funding will help his city extend electricity, water and sewer lines four miles to the new port of entry, creating a zone ripe for new development. He said several Latin American businesses and governments have reached out, interested in setting up U.S. distribution centers for their goods in Douglas.
“The problem is, you know, with people moving from bigger cities down here to work, they’re gonna say, ‘Well, what do you have to offer?’ And right now, we only have Walmart,” Grijalva said.
The mayor hopes special events, like a recent U.S.-Mexico international boxing show, put Douglas on the map, convincing people to settle in the city. He said that can insulate Douglas’ tax base from fluctuations in visits from Mexico influenced by federal policies.
“I’m looking to not be so dependent on Mexico and have Mexico as a luxury,” he said.
According to census data, Arizona’s population grew from just under 7.2 million to over 7.6 million between July 2020 and July 2025. Pinal County’s population grew from about 430,000 to almost 540,000 in that time period, while Cochise County, where Douglas is located, grew ever so slightly from 125,527 residents to 126,332. The recent data is an estimate, as full census counts occur only every ten years.
Arizona’s ten fastest-growing cities between July 2020 and July 2025##
- Coolidge: 48.7%
- Queen Creek: 47.9%
- Colorado City: 40.7%
- Buckeye: 34.3%
- Maricopa: 33.2%
- Casa Grande: 28.8%
- Goodyear: 28.2%
- Eloy: 27.2%
- Tolleson: 26.6%
- Marana: 24.5%
Arizona's ten most shrinking cities between July 2020 and July 2025##
- Florence: -7.5% (contains several prisons whose inmates are counted by the census)
- Winslow: -6%
- Guadalupe: -4.4%
- Clifton: -4.2%
- Gila Bend: -4%
- Page: -3.6%
- South Tucson: -3.6%
- Patagonia: -3.5%
- Paradise Valley: -3.4%
- Tusayan: -3.2%
