$475 Cheap Delta flights St. Louis (STL) to Reykjavik (KEF)

Finding cheap one-way Delta Air Lines flights from STL to KEF from $475 on Expedia is easy --- just filter by "Price (lowest to highest)." Alternatively, check out our affordable round-trip fares from $593 for your next exciting vacation.**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 grab affordable flights from STL to KEF with Delta Air Lines, begin 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 good 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.

Filter your results by "Morning" and "Early Morning" to browse the earliest departures from STL to KEF. Taking off early means flight 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.

Delta Air Lines makes traveling from STL to KEF more comfortable with an excellent in-flight experience and a rewarding loyalty program. You could even start earning points with Delta SkyMiles. Remember to join our free One Key™ rewards program to earn OneKeyCash™*, which can be redeemed on future travel.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.