Jonesboro High School was put on lockdown around 8 a.m. EST, after the shootout a street behind the school.
The incident began when the deputy saw a man speeding and driving recklessly through the school zone. He tried pulling over the vehicle, but the driver sped away into a nearby subdivision.
Neighbors told The Atlanta Journal-Constitution the suspect pulled over, got a rifle out of his trunk and lay in wait, firing at approaching officers, ambushing them.
Police returned fire, though one deputy was injured. The suspect was hit and taken into custody.
Neither the identities nor conditions of the deputy and suspect were released, police said.
"I do know the officer was wearing his [ballistic] vest, and hopefully, the injuries are very minimal," Clayton County sheriff's Chief Deputy Garland Watkins said.
Police did not release a motive for the suspect's actions.