Clayton County is home to Hartsfield-Jackson Atlanta International Airport, the world's busiest passenger airport and the state's largest employer center, with a workforce of more than 56,000. It also has a commuter bus service known as C-Tran.

Clayton State University, founded in 1969 as Clayton Junior College, is located in the city of Morrow. Spivey Hall, one of the Southeast's premier recital halls, is on the Clayton State campus. In addition, the Georgia Archives moved to Morrow from downtown Atlanta in the spring of 2003. One area that remains as a quiet and undisturbed haven for wildlife is the 146-acre Reynolds Nature Preserve.

The Battle of Jonesboro is reenacted annually during the Fall Festival.Two plantation houses, Stately Oaks and Ashley Oaks, are available for tours and hold special holiday events. Clayton County is also the site of the Road to Tara Museum, which houses the world's largest permanent Gone With the Wind exhibition. Jonesboro's survival from the devastation of the Civil War and the period of Reconstruction provided much of the background for Margaret Mitchell's novel.

The population of Clayton County increased 30 percent between 1990 and 2000, to 236,517. In addition to Jonesboro and Morrow, other incorporated cities in the county are Forest Park, Lake City, Lovejoy, and Riverdale.

The largest employers, including Delta Air Lines, are in the transportation, public utility, service, and retail trade sectors. During the 1996 Olympic Games, Jonesboro hosted the beach volleyball competition at Atlanta Beach in Clayton County International Park. The Clayton County Water Authority also attracts visitors from all over the world who come to see the county's natural land application process for the treatment of wastewater. The system purifies the wastewater and, at the same time, fertilizes the land; it also produces palletized fertilizer for the marketplace.