$140 Cheap Spirit Airlines flights Boston (BOS) to St. Thomas (STT)

You'll discover affordable return Spirit Airlines flights from $282 from BOS to STT by organizing your results from "Price (lowest to highest)" on Expedia. Or search for deals from $140 for a one-way trip.**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 Spirit Airlines flights from BOS to STT about one month before you want to go. 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 fare class and itinerary, the best day to book international airfare is usually Sunday. Friday is often the most expensive. Passengers booking on a Sunday can save an average of 17% 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 BOS to STT with Spirit Airlines, filter your results by "Early Morning" and "Morning." Booking 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.

Journey from BOS to STT with Spirit Airlines and you'll enjoy a range of benefits starting with a rewarding loyalty program. When you book through Expedia as a Free Spirit and One Key™ member, you may also earn OneKeyCash™* to spend on select future travel purchases.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.