Can I leave the airport during a layover at ATL?
Yes — domestic passengers can leave and re-enter through security; international layovers require U.S. immigration first.
Domestic layover passengers at Hartsfield-Jackson can freely leave the airport and re-enter through security with a valid boarding pass. The MARTA station inside the Domestic Terminal makes a downtown Atlanta excursion easy — 20 minutes to Five Points station, then 4–6 hours of free time before re-entering security.
International layover passengers can also leave the airport, but must first clear U.S. Customs and Border Protection (CBP) at Concourse E or F. CBP processing takes 25–45 minutes including baggage claim and rescreening. Once you've cleared CBP, you're effectively a domestic passenger and can leave freely.
If you're connecting to another international flight (international-to-international), leaving the airport requires you to formally enter the U.S. through CBP. This adds significant time and may require additional visa documentation depending on your itinerary. For most international-to-international layovers under 8 hours, staying airside is the simpler option.
Plan to be back at the airport security checkpoint at least 90 minutes before your departure. Add 30 minutes for international flights or peak-period travel. TSA PreCheck members can reduce these margins by 15–20 minutes.