$501 Cheap KLM flights St. Louis (STL) to Reykjavik (KEF)

Grab affordable return KLM flights from $645 from STL to KEF by organizing your results from "Price (lowest to highest)" on Expedia. Or look for bargains from $501 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.

Search for KLM flights from STL to KEF about one month before you want to go. The most affordable time to reserve an international flight is generally 18 to 29 days ahead of your travel date when you can save 17% versus booking four to five months in advance. Regardless of fare class or itinerary, the best day of the week to book international airfare is usually Sunday. Friday is often the most expensive. Passengers booking on a Sunday can save 17% on average compared to those who book on a Friday.**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 departures from STL to KEF with KLM, sort your results by "Morning" and "Early Morning." Booking an early flight generally 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.

A 4-star airline rating and the chance to rack up points through KLM Flying Blue are the start of the reasons to fly from STL to KEF with KLM. Plus, by joining Expedia's free One Key™ program, you can receive OneKeyCash™* alongside KLM's loyalty program earnings. It's yours to spend on your next adventure.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.