| Nonstop Flights: Austin to San Francisco $29 r/t â Frontier Frontier has round-trip flights from Austin (AUS) to San Francisco (SFO) for $29, NONSTOP. Flights November to mid-December. Limited availability. Departures on Monday, Friday, and Saturday. Very few extended weekends available. Origin/Destination reversible. Note: Frontier fares do not include a free carry-on bag. Only a small personal item, like a Jansport City Scout backpack is free. You can avoid paying for seat selection if you accept the randomly assigned seat prior to boarding. Note: Frontier seats only have 28-inches of pitch; 2-to-3 inches less space than most other airlines. 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 San Francisco $29 r/t â Frontier . | 
