Several flights have been cancelled or delayed and airport officials said there could be more delays because of the massive power outage.
At least some flights at Atlanta's busy airport have been grounded due to a power outage.
Delta Airlines which use Atlanta as a hub said some diversions were in progress for flights heading to Hartsfield-Jackson.
Chick-fil-A made the rare gesture of opening on a Sunday to deliver more than 5,000 meals to stranded passengers, according to the airport's Twitter page. Officials say the power outage was caused by a fire at an electrical facility that services the world's busiest airport.
Anthony Foxx, who served as USA transportation secretary under President Barack Obama, was among the many travelers stuck for hours on a plane on the tarmac.
Atlanta Mayor Kasim Reed tweeted around 7:30 p.m. ET that power at Concourse F of Atlanta Hartsfield-Jackson International Airport had been restored.
Even passengers whose flights had already landed were affected by the power outage, as it shut off the baggage claim and prevented them from being able to leave with their luggage. They also said arriving worldwide flights were to be diverted to other airports.
American Airlines: Everyone who flew on American Airlines on Sunday received their luggage.
For passengers, "it could be most of the week" because there are not many open seats on other flights in the last week before Christmas, he said. American Airlines canceled around 50 but said it was back on a normal schedule by late morning. He waited on the plane on the tarmac for more than two hours until passengers were allowed to get off and go into a dark airport. On average, 275,000 passengers pass through the airport each day.