The Clayton County Library System was founded in January of 1941 through the efforts of the Jonesboro Women's Club. The library began with a collection of 200 books that the Women's Club borrowed from the WPA. A room was rented above the old Jones Brothers Department Store on South Main Street- across from the railroad depot. Mrs. Mary Barnette became the first librarian.

In 1960 Jonesboro library joined the Flint River Regional Library System, headquartered in Griffin, GA. This alliance allowed Clayton citizens to use the region's larger collection of books, staff, of professional librarians and bookmobile services.

In 1964, ground breaking for a new Jonesboro library began. In 1966, the library opened on the corner of Smith and Lee Streets in downtown Jonesboro--the Jonesboro library branch's current locations. In 1967 the Forest Park Branch opened on Main Street in Forest Park. In 1968 the Riverdale Branch opened, then located on GA Hwy. 85 near Upper Riverdale Rd. In 1975, the Morrow Branch opened, then located in a store front on Old Rex Rd.

In 1981 the libraries of Clayton County were so successful that they left their affiliation with the Flint River Regional System and the Clayton County Library System was formed. In 1988 Headquarters library was built on Battle Creek Road. In 1991 a new Morrow branch was built on Maddox Road. In 1998, a new Riverdale branch was built on Valley Hill Road. The Library System opened the Lovejoy Branch Library its 6th branch in January of 2005 on McDonough Road.

The Clayton County Library Friends group began in June 1950 due, again, to the efforts of the Jonesboro Women's Club and the Clayton County Library Board. Interest dwindled, but in the 1980s, the Friends Group was reorganized and has been a thriving and beneficial part of the library ever since.