The remains were found over the weekend about nine miles from where Cornwell disappeared, said John Bankhead, spokesman for the Georgia Bureau of Investigation. A state forensic pathologist used dental records to identify them as Cornwell's.
Authorities were working to determine a cause of death. A news conference was scheduled for Monday afternoon.
Cornwell's disappearance confounded local authorities. Soon after, investigators found her cell phone about two miles north of where she was last seen, but there was no trace of her until this past weekend.
Details about how the remains were located were not immediately available. Bankhead said more information would be released Monday afternoon.
The bureau was flooded with dozens of tips in December 2009 after investigators released a sketch of a possible suspect and a vehicle that may have been involved. Last January, North Carolina authorities received an anonymous letter from a woman who said the sketch of the suspect looked like her grandson. That woman has not been located, Bankhead said.
Authorities also scoured the car of a 42-year-old man who killed himself after a standoff with Atlanta police in May. They believed James Scott Carringer could have been involved in Cornwell's disappearance because he lived a few miles from where she was last seen and owned a silver Nissan Xterra, the same type of car spotted in the area the night Cornwell went missing.
On Monday, Bankhead would not say whether Carringer was considered a suspect in Cornwell's death.