What Terminal is Sun Country Airlines at ATL? Sun Country Airlines operates from the Domestic Terminal (North Terminal) at Hartsfield-Jackson Atlanta International Airport (ATL) for its passenger services. Passengers can complete check-in, baggage drop, and security screening before proceeding to their designated departure gate. The airline offers affordable domestic flights along with a convenient and comfortable travel experience. For a smooth journey, travelers should arrive at least 2 hours before their scheduled departure.