Southwest Airlines via DealBase discounts Southwest Airlines 1-Way Fares Nationwide with prices starting at $39.98. (On the DealBase landing page, click on "Southwest Airlines" in the top line to see this sale.) That's a buck below last week's fares and the lowest price we could find for select routes today by at least $5. Note that blackout dates and other conditions may apply. Book this travel deal by September 21 for travel from September 26 through March 7, 2018.

All prices, dates, and booking details were valid at the time of publication.