$343 Cheap American Airlines flights San Francisco (SFO) to St. Thomas (STT)

Scoring cheap one-way American Airlines flights from SFO to STT from $343 on Expedia is simple — just filter by "Price (lowest to highest)." Or check out our affordable return fares from $609 for your next exciting adventure.**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.

Search for American Airlines flights from SFO to STT about one month before you want to leave. The most affordable time to reserve an international flight is usually 18 to 29 days ahead of your travel date when you can save 17% versus booking four to five months in advance. No matter your ticket type or itinerary, the best day to book international airfare is usually Sunday. Friday can be the most expensive. Travelers who book on a Sunday can save 17% on average compared to those who book on a Friday.**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.

To find the earliest departures from SFO to STT with American Airlines, filter your results by "Morning" and "Early Morning." Choosing an early flight usually means you'll experience fewer cancellations.**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.