| Nonstop Flights: Austin to/from San Francisco $97-$140 r/t â United United has round-trip flights from Austin (AUS) to San Francisco (SFO) for $97-$140, NONSTOP. Flights January, February, May, and June. Departures on Wednesday, Friday, and Saturday. Very few weekends available. Note: Cheapest flight is on Feb 29, returning Mar 03. Note: United âBasic Economyâ fares do not include a free carry-on bag. Only a personal item (like a small laptop bag) is free. Seats are randomly assigned for free prior to boarding. If you have the United MileagePlus credit-card, use the âfree checked bagâ perk. Note: The personal item size on United flights is smaller (9-in/10-in/17-in) than Frontier or Spirit (8-in/14-in/18-in). We donât charge a subscription fee. All of our deal notifications are available for FREE via Instagram, Facebook, Twitter, our Webpage, and our E-mail list. If you are paying someone a subscription fee for our content, you are being ripped off. Read More Nonstop Flights: Austin to/from San Francisco $97-$140 r/t â United . | 