| Cheap Flights: Austin or San Antonio to/from St. Louis $103-$106 [July-August] r/t â American Airlines Due to the covid-19 pandemic, we do not recommend booking travel with departures between May and June. This fare has departures later in the year. American Airlines has round-trip flights from Austin or San Antonio (AUS/SAT) to St. Louis (STL) for $103-$106 with a connection. Flights July to August. Weekends available. Origin/Destination reversible. Change fees are waived and carry-on bag is allowed for free. You can avoid paying for seat selection by accepting the randomly assigned seat at the gate. Want a notification sent straight to your phone when any new deals are found? Join our Telegram channel and never miss another deal. Patreon supporters receive a recap of all the airfare deals currently available from Austin and San Antonio everyday. We donât charge a subscription fee. Our deal notifications are available for FREE via Instagram, Facebook, Twitter, Telegram, our Webpage, and our E-mail list. If you are paying someone a subscription fee for this content, you are being ripped off. Read More Cheap Flights: Austin or San Antonio to/from St. Louis $103-$106 [July-August] r/t â American Airlines . | 