$39 Cheap United flights San Francisco (SFO) to San Diego (SAN)

Apply the "Price (lowest to highest)" filter on Expedia to look for cheap United Airlines return flights from $87 from SFO to SAN. Affordable one-way fares from $39 are available as well.**These prices were available on Expedia within the past 7 days, for flights departing within the next year. Prices and availability are subject to change. Additional terms apply.

Begin your search one to three months before your departure to score cheaper fares on United Airlines flights from San Francisco Intl. Airport (SFO) to San Diego Intl. Airport (SAN). You can save 25% by booking your domestic flight 34 to 86 days in advance compared to last-minute reservations made 6 to 12 days out. You could also cut costs by buying your fare on a Sunday, as it's 6% cheaper on average than a Monday, the most expensive day to book.* Nail your timing, and you can enjoy significant savings on domestic trips.*Ideal booking window recommendation is based on average round-trip ticket prices for January through November for 2024. Best day of the week to book recommendation is based on average round-trip ticket prices for January through October 2024. All data sourced from ARC's global airline sales database.

Setting off from SFO at 8:30AM UTC-8, the earliest United Airlines flight to SAN lands at 10:09AM UTC-8. Traveling earlier in the day means you'll be less likely to experience delays.* Not an early riser? The last United Airlines flight from SFO to SAN departs at 10:35PM UTC-8 and touches down at 12:14AM UTC-8.*Most reliable time of the day recommendation is based on January through August 2024 flight status data sourced from OAG's global flight data platform.

A rewarding loyalty program and the opportunity to collect points through United Mileage Plus are the start of the reasons to travel from SFO to SAN with United Airlines. Plus, by joining Expedia's free One Key™ program, you can receive OneKeyCash™* on top of any airline loyalty program earnings. It's yours to spend on future bookings.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.