$139 Cheap Delta flights St. Louis (STL) to Boston (BOS)

Use the “Price (lowest to highest)” filter on Expedia to look for cheap Delta Air Lines round-trip flights from $249 from STL to BOS. Affordable one-way tickets from $139 are also available.**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.

Look for one-way or return flights to Boston in January or February. You could find a cheap fare with Delta Air Lines during these off-peak times.

To find cheap Delta Air Lines fares from Lambert-St. Louis Intl. Airport (STL) to Logan Intl. Airport (BOS), 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 affect the cost. Sunday is typically the cheapest, while Monday is often the most expensive for domestic flights. You can save 6% on average by booking 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.

To figure out if there’s a direct journey from STL to BOS with Delta Air Lines or another airline, check the “Nonstop” filter when looking for tickets.

To find the earliest departures from STL to BOS with Delta Air Lines, filter your results by “Early Morning” and “Morning.” Booking an early flight usually means you’re less likely to experience 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.

Logan Intl. Airport (BOS) is the primary Boston hub for Delta Air Lines flights from Lambert-St. Louis Intl. Airport (STL).

Heading from STL to BOS with Delta Air Lines means enjoying a host of benefits, including an excellent in-flight experience and a rewarding loyalty program. Plus, when booking through Expedia, One Key™ members can collect OneKeyCash™* to redeem on select future travel purchases. That’s on top of the Delta SkyMiles points you can earn with Delta Air Lines.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.

Depending on the type of fare you purchased, a fee may apply if you cancel or reschedule your flight more than 24 hours after confirmation. To secure plane tickets with more flexibility, select our “Changes included” and “No cancel fee” boxes when looking for flights. For more information on modifying or canceling your reservation, head to “Trips,” select your flight and tick “Manage Booking.”