Nancy Gordeuk, who also served as principal of TNT Academy in Stone Mountain, was fired by the board of directors after her comments were caught on video and went viral.
In a letter obtained by NBC affiliate WXIA, Chairwoman Heidi Anderson said the decision was made "in light of recent events" and that educators would "continue to prioritize support for most of our recent graduates."
At the ceremony, Gordeuk mistakenly dismissed attendees before the valedictorian spoke, the station reported. She asked them to return to their seats, then said amid the confusion: "Look who's leaving, all the black people."
Gordeuk said later that people were being disruptive when the valedictorian attempted to speak, and that she was frustrated. "When I looked up, all I saw was black families leaving, and thus the comment," she told NBC News.
"I didn't know 'black people' was a racist term. I didn't say the N-word or anything like that 'cause that isn't in my vocabulary," Gordeuk added.
She also apologized for her "racist comment" and asked for forgiveness.