$109 Cheap Delta flights St. Louis (STL) to Key West (EYW)

Apply the “Price (lowest to highest)” filter on Expedia to look for cheap Delta Air Lines return flights from $217 from STL to EYW. Affordable one-way tickets from $109 are available too.**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.

September is one of the cheapest months to jet away to Key West with Delta Air Lines. You could also find fantastic deals on return and one-way tickets in August.

Start searching one to three months before your departure to find cheaper fares on Delta Air Lines flights from Lambert-St. Louis Intl. Airport (STL) to Key West Intl. Airport (EYW). You can save 25% by booking your domestic flight 34 to 86 days in advance compared to last-minute reservations made 6 to 12 days out. You could also reduce costs by buying your fare on a Sunday, as it’s 6% cheaper on average than a Monday, the most expensive day to book.* Nail your timing, and you can enjoy significant savings on domestic flights.*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 see if there’s a direct journey from STL to EYW with Delta Air Lines or any other carriers, use our “Nonstop” filter when searching for flights.

To find the earliest departure from STL to EYW with Delta Air Lines, filter your search by “Morning” and “Early Morning.” Booking an early flight generally 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.

Take a Delta Air Lines flight from Lambert-St. Louis Intl. Airport (STL) to Key West, and you’re most likely to arrive at Key West Intl. Airport (EYW). This is the airline’s main hub in this destination.

Traveling from STL to EYW with Delta Air Lines means enjoying a variety of perks, such as an excellent in-flight experience and a rewarding loyalty program. Plus, when you book through Expedia, One Key™ members can collect OneKeyCash™* to use on select future travel purchases. That’s in addition to 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 ticket type you purchased, a fee typically applies if you cancel or change your flight more than 24 hours after it’s confirmed. To find tickets with more flexibility, select our “No cancel fee” or “Changes included” filter while looking for flights. To learn more about changing or canceling your reservation, visit “Trips,” select your flight and tick “Manage Booking.”