Greenlee County is located in the southeastern part of the U.S. state of Arizona. As of the 2010 census its population was 8,437. The county seat is Clifton. It is the least populous county in the state of Arizona, with the most populous county being Maricopa.
The economy of Greenlee County is dominated by the Morenci Mine, the largest copper mining operation in North America, and one of the largest copper mines in the world.As of 2008, the mine complex, owned by Freeport-McMoRan, had about 4,000 employees.
Greenlee County is part of the Safford Micropolitan Statistical Area.