Get round-trip flights on Southwest Airlines with rates from $106 on Airfarewatchdog. We found the lowest fares on flights between Atlanta and Detroit with advanced booking. Flights from Atlanta to Baltimore start at $126. You can enter your own travel dates and locations to find fare prices on Airfarewatchdog. Some flights require advance bookings or travel on specific days of the week. There's also a sale going on at Southwest Vacations, where you can save $200 on international vacation packages or $100 off domestic vacation packages. Taxes, fees, and restrictions may apply.