$240 Cheap United flights San Francisco (SFO) to Key West (EYW)

Grab affordable round-trip United Airlines flights from $335 from SFO to EYW by organizing your results from "Price (lowest to highest)" on Expedia. Or search for options from $240 for a one-way journey.**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.

For cheap United Airlines fares from San Francisco Intl. Airport (SFO) to Key West Intl. Airport (EYW), start searching one to three months before your planned departure. Reserving domestic flights 34 to 86 days in advance could save you 25% compared to booking just 6 to 12 days ahead. The day you book can also impact the overall cost. Sunday tends to be the cheapest, while Monday is often the most expensive for domestic flights. You can save 6% on average by booking your flight on a Sunday.**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.

Sort your results by "Morning" and "Early Morning" to browse the earliest departures from SFO to EYW. Taking off early means flight cancellations are less likely.**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 ability to rack up points through United Mileage Plus are the start of the reasons to depart from SFO to EYW with United Airlines. Plus, when you sign up to Expedia's free One Key™ program, you can earn OneKeyCash™* on top of United Airlines's loyalty program earnings. It's yours to spend on your next adventure.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.