Police sources said the shootings occurred at two separate locations early Friday evening in Appling.
Four victims died at the scene, while the fifth one died on the way to hospital, Xinhua news agency reported.
Captain Andy Shedd with the Columbia County Sheriff's office said 50-year-old Wayne Anthony Hawes' body was discovered on Saturday by the authorities in his Georgia home.
Police believe the shootings stemmed from a domestic dispute, and that the suspect subsequently set his home on fire and allegedly killed himself.
The identities of the victims remain unclear.