$164 Cheap United flights Boston (BOS) to St. Thomas (STT)

Grab affordable return United Airlines flights from $311 from BOS to STT by sorting your results from "Price (lowest to highest)" on Expedia. Or search for deals from $164 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.

To get affordable flights from BOS to STT with United Airlines, start your search about one month before your intended departure. You can save 17% when you lock in your international tickets 18 to 29 days ahead instead of booking four to five months in advance. Another tip? Booking on Sunday offers average savings of 17% compared to Friday (the most expensive day).**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 departure from BOS to STT with United Airlines, filter your results by "Early Morning" and "Morning." Choosing an early flight generally 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.

Travel from BOS to STT with United Airlines and look forward to a host of benefits starting with a rewarding loyalty program. When you book through Expedia as a United Mileage Plus and One Key™ member, you could also earn OneKeyCash™* to redeem on select future travel purchases.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.