$293 Cheap United flights St. Louis (STL) to St. Thomas (STT)

Grab budget-friendly return United Airlines flights from $437 from STL to STT by organizing your results from "Price (lowest to highest)" on Expedia. Or search for deals from $293 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 discover affordable flights from STL to STT with United Airlines, start your search about one month before your planned 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 useful 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 STL to STT with United Airlines, sort your results by "Early Morning" and "Morning." Booking an early flight usually means 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 chance to rack up points through United Mileage Plus are the start of the reasons to depart from STL to STT with United Airlines. Plus, when you join Expedia's free One Key™ program, you can earn OneKeyCash™* on top of any airline loyalty program earnings. You can put it toward your future trips.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.